Question

resolva a equação do 1 grau 
5x-3+x=2x+9

Answer 1

5x - 3 + x = 2x + 9
5x + x - 2x = 9 + 3
4x = 12
x = 12 : 4
x = 3

Answer 2

5x - 3 + x = 2x + 9
5x + x - 2x = + 9 + 3
6x - 2x = 12
4x = 12
x = 12
       4
x = 3
Confirmando:
5 * 3 - 3 + 3 = 15
2 * 3 + 9 = 15