21x - 15x + 4x - 10 = 0
21х-15х+4х=10х 10х-10=0 х=10-10 х=0
1) 21x - 15x = 6x 3) 10x - 10 = 0 2) 6x + 4x = 10x 10x = 0 + 10 X= 1