Answer:
y=4, -4
Step-by-step explanation:
2^2 + (2√3)^2 = y^2
4+ (2√3)^2 = y^2
y^2=4+12 (here we square the values inside bracket which turns 2 into 4 and when you square a square root it gets rid of the root so you are left with 3 which is multiplied to 4 and you get 12.)
y^2= 16
y=4, -4 (when you square root a positive value you get one positive and one negative answer because here (-4) x (-4) = 16 (because multiplying two negatives gives us a positive.
