Răspuns :
36x-27 - 21x-24 = 7x+21-24
15x - 51= 7x -3
15x-7x= -3 + 51
8x = 48=> x= 48/8 = 6
36x-27-21x-24=7x+21-24
36x-21x-7x=21-24+27+24
8x=48
x=6
36x-21x-7x=21-24+27+24
8x=48
x=6