Calculați : 6x +3x = 2x + 49

Răspuns :

9x=2x+49/-2x
7x=49
x=49÷7
x=7
6x+3x=2x+49
9x=2x+49
9x-2x=49
7x=49
x=49:7
x=7
V: 6x7+3x7=2x7+49
    42+21 = 14+49
    63 = 63