20 - (30 -50) x 10 = 20 - (-20) x 10
= 20 - 20 x 10
= 0 x 10
= 0
where is the mistake?

A. but. i don’t nohxbzbz

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.