2^3/10^(-2) -2/7^(-2) ?

Question

I need help!!!

Answer 1

the way you wrote it down makes it hard to read...

maybe a hint will help you:

if you have a negative exponent, the value of the expression stays the same if you use the reciprocal value with the positive exponent

x°(-2) = 1 / x°2

Answer 2

I think you are trying to subtract these two fractions.  When you have a base with a negative exponent move it to the other side of the fraction and make the exponent positive.  For instance, x^(-6) = 1/x^6 and 1/x^(-5) = x^5.  In your case,

[2³/10^(-2)] - [2/7^(-2)] =

[2³*10²] - [2*7²] =  

2(2²*10² - 7²) =

2(2*2*10*10 - 7*7) =

2(4*100 - 49) =

2(400 - 49) =

2*351 =

702

Hope this helps you!