7. Simplify this what’s the answer?

first the square root of 4 is 2 so we can sub that in.
now we have 2(2*2)^-2.
2 * 2 of course is 4
with 2(4)^-2, keep in mind that negative exponents just mean to "flip" the number and turn the exponents positive.
so 4^-2 is the same as 1/4^2 or 1/16.
finally 1/16 * 2 = 2/16. 2/16 simplified is 1/8.