Answer:

Step-by-step explanation:
we have

Solve for a
That means ----> Isolate the variable a
Factor 3 in the numerator right side

Simplify right side

subtract a both sides


subtract 1 both sides


Rewrite

She is wrong because she did the square root of 25 multiplied by 2, she should have just done the square root of 50.
For the second part the square root of 50 is 7.07 which rounding would equal 7.1.
Hope this helps.(ノ◕ヮ◕)ノ*:・゚✧