Question

Which value of a solves the equation

a^-2 = 1/100

Answer 1

a = 10 or a = -10

Explanation:

a^-2 = 1/100

We know 100 = 10^2

a^-2 = 1/10^2

We know 1/b^c = b^-c

1/a^2 = 1/ 10^2

Multiply by a^2 on each side

a^2 *1/a^2 = 1/ 10^2 *a^2

1 = a^2/10^2

Multiply by 10^2 on each side

1 0^2= a^2/10^2 * 10^2

10^2 = a^2

Take the square root of each side

sqrt(10^2) = sqrt(a^2)

±10 =a