Nice to see problems of this kind. I never recall seeing them in all of the math classes I had.
@devonwilson57762 ай бұрын
Greetings. The answer is 3. 4^3X-6=64 is 4^3X-6=4^3. Since the bases are equal, the exponents are also equal. That is 3X-6=3, 3X=9, adding 6 to both sides of the expression, and 3X/3=9/3, dividing each sides by 3 gives X=3.
@johnmarchington31462 ай бұрын
When you discussed the logarithmic approach and you had log64, you could have mentioned that that would be equal to log4³ - and thus 3log4 - and as that was being divided by log4, the answer would have been 3. Another excellent video. Thanks again.
1. We have the equation: 4^(3x - 6) = 64. 2. Notice that we can rewrite 4 and 64 has powers of 2; so we have: (2^2)^(3x - 6) = 2^6. 3. Now, we’ll use the rule, which says that if x^m = x^n, then m = n; so we now have a basic equation: 2(3x - 6) = 6. 4. Now we distribute the 2, so we have: 6x - 12 = 6. 5. Now we move the 12 to the other side: 6x = 18. 6. Finally, we divide the equation by 6: x = 3. Final ans: x = 3. Ez
@laurendoe1682 ай бұрын
Even easier - 64 is 4 cubed.
@mercy36482 ай бұрын
@@laurendoe168you’re right. But I love math and believe it or not, I don’t like “shortcuts”. I enjoy doing math the “hard way”, you know?
@laurendoe1682 ай бұрын
@@mercy3648 LOL :D I must admit that the first thing I thought of when I saw the problem was using a common base of 2... until I noticed that a common base of 4 could also be used.
@Kleermaker10002 ай бұрын
Only two fundamentally different ways: 1) 3 X - 6 = 3 etc. and 2) the logarithmic method.
@tomtke73512 ай бұрын
Inspection suggests 4^3=64 Might we conclude 3x-6=3 3x=9 x=3 VERIFY 4^(3X-6)=64 with x = 3? 4^((3×3)-6)=?64 4^(9-6)=?64 4^3=?64 64=❤64✔️
@chrisdissanayake69792 ай бұрын
4^3x-6 = 64 64= 4^3 4^3x-6 = 4^3 3x-6 = 3 3x = 3+6 3x = 9 x = 9 divided by 3 x = 3
@richardl67512 ай бұрын
In this case Log(base 10) or Ln can be used.
@Ayelmar2 ай бұрын
Solved in my head at the thumbnail, the answer is x=3. Here's the process I used to get that answer: First, we figure out what power of 4 = 64. 4^1 = 4; 4^2 = 16, and so 4^3 = 64. Therefore, 3x - 6 has to equal 3. Using basic algebra, we get: 3x - 6 = 3 Subtract (-6) from both sides: 3x = 9 Divide both sides by the coefficient, 3: x = 3. And so 4^3 = 64. (And it basically gets back to powers of 2 by a roundabout path....😉 )
@stevenjohnson11432 ай бұрын
Knowing 4^3 =64 so the final exponent must be 3 if 3x-6=3 then adding 6 to both sides get 3x=9 finishing by dividing 3 x°3