Question

If 12^x^^2^+5x-4 =12^2x+6, what could be the value of x?

x = 2
x = –5
x = 2, x = –5
no solution

Answer 1

Answer: x = 2, x = - 5

Step-by-step explanation:

1) The given expression is not clear.

I will rewrite it using the math editor for better understanding


`12^(x^2+5x-4)=12^(2x+6)`

2) Since the bases are equal, the exponents are equal too.

=> x^2 + 5x - 4 = 2x + 6

Solve that quadratic equation step by step:

3) transpose 2x + 6 to the left side:

x^2 + 5x - 4 - 2x - 6 = 0

4) Combine like terms:

x^2 + 3x - 10 = 0

5) Factor:

(x + 5) (x - 2) = 0

6) Equal each factor to 0

x + 5 = 0 => x = - 5
x - 2 = 0 => x = 2

Those are the solutions x = - 5 and x = 2