Question

resolver la siguiente ecuacion lineal
x + 9x = 90

Answer 1

x +9x =90
10x = 90
x = 90/10
x = 9

comprobacion
x +9x = 90
9 +9*9 = 90
9 +81 =90
90  = 90

Answer 2

x+9x=90
90=10x
90%10=9
x=9