Question

5x=16
12x-20=0
3x^2=27
3y-2=7-y
-8z+4=-5+10z

Answer 1

 5x = 16
  x = 16/5

3x^2 = 27
  x^2 = 27/3
  x^2 = 9
  x = +/-√9
  x = +/- 3 ó x1 = 3 ; x2 = -3

3y - 2 = 7 - y
3y + y = 7 + 2
4y = 9
y = 9/4

-8z + 4 = -5 + 10z
4 + 5 = 10z + 8z
9 = 18z
z = 9/18
z = 1/2