Question

3x - ( 9х + 13 ) = 7х + 13

Answer 1

3x - ( 9х + 13 ) = 7х + 13
3х - 9х -13 = 7х + 13
3х - 9х - 7х = 13 +13
-13х = 26
х = -2

Answer 2

3x - ( 9х + 13 ) = 7х + 13
3x - 9х - 13 = 7х + 13
3x - 9х - 7х = 13+13
-10x=26
x= 26 / -10
x=2,6