Substitute t=10^x and recall that 100^x=(10^x)^^2 and 1000^x=(10^x)^3. Than you get t+t^2=t^3 t^3-t^2-t=0 t*(t^2-t-1)=0 t=0 or t^2-t--1=0 t=0 or t=(1+sqrt(5)/2 or t=(1+sqrt(5)/2 Reember, tht t=10^x>0, so t=0 and t=(1-sqrt(5) willll be rejected So we get 10^x=(1+sqrt(5)/2 x=llog((1+sqrt(5))/2)
2^x=a a³-a=120 5³-5=125-5=120 a=5 2^x=5 x=log5/log2= x≈0.699/0.301≈2.322 Deviation is about 0.0003 8^2.322-2^2.323≈120.018
@rarocon3 күн бұрын
8 + 2 = 10
@veikkoritvaniemi76274 күн бұрын
Wrong solution. Should be square -48 not -58.
@joliettravelerКүн бұрын
spotted that right away.
@AvikDey-z6y4 күн бұрын
(a-b) ^2=(a+b) ^2 - 4ab =10000-4000 =6000 =100×60 Or (a-b) =10√60 Now a+b=100 a-b=10√60 Next 2a =100+10√60 Or a=50+5√60 and b=50-5√60
@uroojmehdi58014 күн бұрын
Gud sir thankx my dear
@chaklai46634 күн бұрын
Wonderful and respected. 🙏💖
@ОлександрПрадеус4 күн бұрын
-5. 25-(-125)=150
@1234larry14 күн бұрын
An easy problem, but I wonder why you chose such large numbers that are prime for the solution set. It’s just makes the arithmetic a little harder, but I don’t see the point.
@chaklai46634 күн бұрын
I saw too many maths KZbin show how to solve arithmetics like this, but no one will choose a larger prime numbers. Just curious, I am sorry.🫡
@erictu16784 күн бұрын
my answer is x=51/2 1/2 and y = 49/ 2 1/2; do not know how to type root of 2 square; any catch for this problem?
@wes96274 күн бұрын
Best Trick? a=97/2+c, b=97/2-c, (97/2+c)(97/2-c)=997, c^2=97^2/4-997=5421/4, a=(97+√5421)/2, b=(97-√5421)/2
They call everything Olympiad problem. These are just indices.
@에스피-z2g2 сағат бұрын
I don't think so.
@AlphaSorceror2 сағат бұрын
Just count the number of square roots. There are 5 so the LHS index power must be 1 / 2^5) = 1/32 X^(1/32) = 2^3 Then solve. What nonsense that this is Olympiad?
@srinivasanrao10335 күн бұрын
Very nice solutions
@Mathsfocus86105 күн бұрын
Thank you! Cheers!
@nenaud5 күн бұрын
writing correctly your signs, your letters and your numbers will ease the understanding of your demonstration thanks for this help anyway
@07Pietruszka19575 күн бұрын
You lost third answer x=-0.766665
@abeljacobi42215 күн бұрын
Right, there aren't only integer solutions. x ≈ -0.766665 (or with a few more decimals x ≈ -0.766664695962123093111)
@werbone6 күн бұрын
I wish people would stop using Olympiad to attract views of very straightforward problems.
@Салют-я5с6 күн бұрын
а=-5
@chaklai46636 күн бұрын
a+b=97 ab=997 Could you solve it.🤔
@Mathsfocus86105 күн бұрын
Be expecting that in my next video tomorrow
@羁绊在可视宇宙之外6 күн бұрын
2or3😂
@stpat76146 күн бұрын
Isn't there a complex solution? 9^x + 3^x = 20 (3^2)^x + 3^x = 20 3^(2 * x) + 3^x = 20 3^(x * 2) + 3^x = 20 (3^x)^2 + 3^x = 20 Let u = 3^x (3^x)^2 + 3^x = 20 => u^2 + u - 20 = 20 - 20 => u^2 + u - 20 = 0 => 1 * u^2 + 1 * u + (-20) = 0 Let a = 1, b = 1, c = -20 1 * u^2 + 1 * u + (-20) = 0 => a * u^2 + b * u + c = 0 u = (-b +/- sqrt[b^2 - 4 * a * c]) / (2 * a) u = (-1 +/- sqrt[1^2 - 4 * 1 * (-20)]) / (2 * 1) u = (-1 +/- sqrt[1 + 80]) / (2) u = (-1 +/- sqrt[81]) / 2 u = (-1 +/- sqrt[9^2]) / 2 u = (-1 +/- 9) / 2 u = (-1 + 9) / 2, or u = (-1 - 9) / 2 u = 8 / 2, or u = -10 / 2 u = 4, or u = -5 Remember, u = 3^x u = 4, or u = -5 => 3^x = 4, or 3^x = -5 Suppose 3^x = 4 3^x = 4 log(3^x) = log(4) x * log(3) = log(4) x * log(3) / log(3) = log(4) / log(3) x * log_3(3) = log_3(4) x * 1 = log_3(2^2) x = 2 * log_3(2) Suppose 3^x = -5 3^x = -5 ln(3^x) = ln(-5) x * ln(3) = ln(-1 * 5) x * ln(3) / ln(3) = ln(-1 * 5) / ln(3) x * log_3(3) = (ln[-1] + ln[5]) / ln(3) x * 1 = ln(-1) / ln(3) + ln(5) / ln(3) x = ln(e^[i * tau / 2]) / ln(3) + log_3(5) x = (i * tau / 2) * ln(e) / ln(3) + log_3(5) x = (i * tau / 2) * 1 / ln(3) + log_3(5) x = i * tau / (2 * ln[3]) + log_3(5) x1 = 2 * log_3(2) x2 = i * tau / (2 * ln[3]) + log_3(5)
@oliviercresson16436 күн бұрын
Expliquer vous
@kommentar17096 күн бұрын
From equation (1) we get a = 11-b. Insert this into (2) to get (11-b)b = 111 -> 11b - b² = 111 -> b²-11b-111 = 0. Now solve for b1,2 by applying the quadratic formula to get b1 = 33/2 and b2 = -11/2. Insert either solution into equation (1) to find that in case of b1, a1 would become -11/2, while in case of b2, a2 would calculate as 33/2. Hence there are two reciprocal solutions for real numbers of a and b: [a1,b1] = [-11/2,33/2] and [a2,b2] = [33/2,-11/2].
@tonyennis17874 күн бұрын
Your answers are incorrect. 16.5 * -5.5 <> 111
@1234larry16 күн бұрын
Not meaning to criticize, because I’m sure your videos are valuable for people who are just beginning to understand algebra, but can you occasionally put videos which are more challenging? Thank you.
@quertzvonmaskevt15836 күн бұрын
Where did you get 15?
@1234larry16 күн бұрын
When you factor 6000, two factors in which one is a “perfect square” are 400 times 15, 400 being the perfect square.
@Mathsfocus86106 күн бұрын
400 x 15 = 6000 ✓ 400=20, multiply by √15
@varshiniexim38236 күн бұрын
Excellent. Great job ❤
@Ghorgolla7 күн бұрын
Thanks mate! :)
@prollysine7 күн бұрын
let u=3^x , u^2+u-20=0 , (u-4)(u+5)=0 , u= 4 , / -5 < 0 not a solu for x/ 3^x=4 , x=log4/log3 , 1 -4 test 9^x+3^x=16+4 , --> 20 , OK , 5 -20
@stpat76147 күн бұрын
a + b = 11 a + b - b = 11 - b a = 11 - b ab = 111 (11 - b)b = 111 11b - b^2 = 111 11b - b^2 - 111 = 111 - 111 -b^2 + 11b - 111 = 0 b^2 - 11b + 111 = 0 b = (-[-11] +/- sqrt[(-11)^2 - 4*1*111]) / (2 * 1) b = (11 +/- sqrt[121 - 444]) / (2) b = (11 +/- sqrt[-333]) / 2 b = (11 +/- sqrt[-1 * 3 * 3 * 37]) / 2 b = (11 +/- sqrt[-1] * sqrt[3^2] * sqrt[37]) / 2 b = (11 +/- i * 3 * sqrt[37]) / 2 b = (11 + i * 3 * sqrt[37]) / 2, or b = (11 - i * 3 * sqrt[37]) / 2 b1 = (11 + i * 3 * sqrt[37]) / 2 b2 = (11 - i * 3 * sqrt[37]) / 2 a1 = 11 - b1 a1 = 11 - (11 + i * 3 * sqrt[37]) / 2 a1 = 11 * 2 / 2 - (11 + i * 3 * sqrt[37]) / 2 a1 = 22 / 2 - (11 + i * 3 * sqrt[37]) / 2 a1 = 22 / 2 + (-11 - i * 3 * sqrt[37]) / 2 a1 = ([22 - 11] - i * 3 * sqrt[37]) / 2 a1 = (11 - i * 3 * sqrt[37]) / 2 a2 = 11 - b2 a2 = 11 - (11 - i * 3 * sqrt[37]) / 2 a2 = 11 + (-11 + i * 3 * sqrt[37]) / 2 a2 = 11 * 2 / 2 + (-11 + i * 3 * sqrt[37]) / 2 a2 = 22 / 2 + (-11 + i * 3 * sqrt[37]) / 2 a2 = ([22 - 11] + i * 3 * sqrt[37]) / 2 a2 = (11 + i * 3 * sqrt[37]) / 2 { (a1, b1), (a2, b2) } = { ([11 - i * 3 * sqrt(37)] / 2, [11 + i * 3 * sqrt(37)] / 2), ([11 + i * 3 * sqrt(37)] / 2, [11 - i * 3 * sqrt(37)] / 2) }
@gerhardb12278 күн бұрын
subst u^32 = sqrt(x) => u^31= 8 u = 8^(1/31) resubstitution: sqrt(x) = 8^(32/31) x = 8^(64/62) = 8^(32/31)
@lionelfischer82408 күн бұрын
Trivial try = -5. Finished in 30 s.
@wyterminator37368 күн бұрын
Another method.. SQRT(3^x * SQRT( (9^x) * SQRT(81^x ) ) ) = 81 = 3 ^ 4 where SQRT(81 ^ X) = SQRT(9 ^ 2x) = 9^x SQRT( 3^x * SQRT( 9^x * 9^x ) ) = 3 ^ 4 where SQRT( 9^x * 9^x ) ) = 9 ^ x = 3 ^ 2x SQRT( 3 ^ x * 3 ^ 2x ) = 3 ^ 4 SQRT( 3 ^ 3x ) = 3 ^ 4 where SQRT( 3 ^ 3x ) = 3 ^ (3/2)x 3 ^ (3/2)x = 3 ^ 4 where 3x/2 = 4 multiply each side by 2/3. x = 8/3
@jeffreyhudale56338 күн бұрын
262143
@oscargraveland8 күн бұрын
You still need to verify x2,y2
@AVR07099 күн бұрын
The answer is Log(φ )/Log(5). I think you have done a mistake somewhere.
@nasrullahhusnan22899 күн бұрын
(5^x)+(25^x)=125^x [(5³)^x]-[(5²)^x]-(5^x)=0 (5^x)³-(5^x)²-(5^x)=0 Divide by (5^x)≠0: (5^x)²-(5^x)-1=0, a quadratic equation in 5^x: 5^x≠½[1±sqrt(5)] As 5^x can't be negative, 5^x=ß is golden ratio --> x=[log(ß)]/log(5)
@nasrullahhusnan22899 күн бұрын
What you get are three pairs of real numbers, not of natural number.
@Mathsfocus86106 күн бұрын
That's why it was concluded that no solution. Thanks