precal question

Question

Solve the equation. (Enter your answers as a comma-separated list.)

x²7^x − 64(7^x) = 0

x = 

 

Answer 1

x²7^x − 64(7^x) = 0

7^x(x² - 64) = 0

7^x(x + 8)(x - 8) = 0

Then set each piece equal to zero:

7^x = 0 (no solution - there are no x values resulting in 7^x equaling zero)

x + 8 = 0 or x = -8

x - 8 = 0 or x = 8

So x = 8 and x = -8