Question

In the expression below if a = 4, what value of b is needed for the expression to have a value of 81?

12a3b7(ab)-4

Answer 1

[AI-generated answer — Bot GPT 3.5]

In the expression 12a3b7(ab)-4, if a = 4, we can substitute the value of a into the expression to get:

12(4)3b7(4b)-4 = 12(64)b(28)-4

Now simplify the expression:

12(64)b(28)-4 = 768b(28)-4 = 21504b-4

To find the value of b that makes the expression equal to 81, set the expression equal to 81 and solve for b:

21504b-4 = 81
21504b = 85
b = 85 / 21504
b = 0.00396

Therefore, the value of b needed for the expression to have a value of 81 when a = 4 is b = 0.00396.