Question

16-x=x+25


e a 20x-13=20+9x

Answer 1

a) 
16 - x  = x + 25
- x - x = 25 - 16
- 2x =  9 (-1)
2x = - 9
x = - 9/2
x = - 4,5

b)
20x - 13 = 20 + 9x
20x - 9x = 20 + 13
11x = 33
x = 33/11
x = 3