1) у^2-10=39;
2) х^2+5=30;
3)5t^2-3=77;
4) 1/2х^2=8/9;
Как решить? Помогите пожалуйста.

1) у^2 -10 = 39

у^2 = 39-10

у^2 = 29

у = -7

у = 7

2) х^2 + 5 = 30

х^2 = 30 - 5

х^2 = 25

х = 5

х = -5

3) 5t^2 - 3 = 77

5t^2 = 77 + 3

5t^2 = 80

t^2 = 80 ÷ 5

t^2 = 16

t = 4

t = -4

4) 1/2x^2 = 8/9

2× 1/2x^2 =2 × 8/9

x^2 = 16/9

×= - 4/3

x = 4/3