Need help on this question:

Solve 4y^{4}- 7y^{2}- 36 = 0

y =

Also need help with this question:

Solve (square root of 3s +4) + 2s = 12

s =

Also need help with this question:

Solve (square root of 17 - 2x) = (square root of 8 - x) + 1

x =

Also need help with this problem:

Solve: Let u = (square root of x-2)

(square root of x-2) squared - 12 (square root of x) + 51 = 0

x =

Hope someone can help.