Question

7-x/2 = x+7/ 4

20/y+8=4/5

Answer 1

7-x/2 = x+7/ 4

7 - x      x + 7
------- = -------- ( só cruzar)
  2           4

2(x + 7) = 4(7 - x)
2x + 14  = 28 - 4x
2x + 14 + 4x = 28
2x + 4x = 28 - 14
6x = 14
x = 14/6   ( divide AMBOS por 2)
x = 7/3


20/y+8=4/5


20           4
------- = ------  ( só cruzar)
y +8        5

4(y + 8) = 5(20)
4y + 32 = 100
4y = 100 - 32
4y = 68
y = 68/4
y = 17