Question

Use the following equation:
log2x + log2(x – 7) = 3

The third step would be to:


Select one:


a. Graph the function.

b. Take the log of each side.

c. Square the expression.

d. Factor the resulting quadratic equation.

Answer 1

@phi @kc_kennylau

Answer 2

log_2(x) + log_2(x-7) = 3
log_2[x(x-7)] = 3
x(x-7) = 8
x^2-7x = 8 <----- third step
x^2-7x-8 = 0
(x-8)(x+1) = 0
x=8 or x=-1(rej)

Answer 3

There are so many approaches, I don't understand why particularly ask for the third step...

Answer 4

is it take the log of each side?

Answer 5

@satellite73

Answer 6

@phi

Answer 7

@satellite73