упростить выражения а)6p+8q-9p-3qб)7y+(4-2y)-(12+9y)в)2-6(7x+3)

a) 6p+8q-9p-3q = -3p+5q = 5q-3p
б) 7y+(4-2y)-(12+9y) = 7y+4-2y-12-9y = -4y-8
в) 2-6(7x+3) = 2-42x-18 = -16-42x