One more math problem?

Question

how do you solve this?

(x-1) ^ -2 =25

thanks
answer is 4/5 or 6/5

Answer 1

Negative exponents mean reciprocals, so:

(x - 1)^(-2) = 25

(x - 1)^2 = 1/25

x - 1 = +/- sqrt(1/25)

x - 1 = +/- 1/5

x = 1 +/- 1/5

So, x = 1 + 1/5 = 6/5 or x = 1 - 1/5 = 4/5

Answer 2

Just to break it down a little further, so that you can see why the first person's answer is correct:

Since a negative exponent is a reciprocal, you could have your solution look like this--

(x-1)^-2=25
1/((x-1)^-2)=25

Multiply the denominator out:

(x-1)^2/(x-1)^2=25((x-1)^2)
1=25((x-1)^2)
Now let's get rid of the 25 by dividing it out:

1/25 = (x-1)^2

sqrt both sides:

+-1/5= x-1

x=1 +- 1/5 = 4/5 or 6/5

Answer 3

sorry math is not my strong point!

best of wishes!