已知方程组3x+2y+6=0,则代数式4(3x+2y)-3(2x-5)-4y的值为?
问题描述:
已知方程组3x+2y+6=0,则代数式4(3x+2y)-3(2x-5)-4y的值为?
答
∵3x+2y+6=0
∴3x+2y=-6
∴4(3x+2y)-3(2x-5)-4y
=12x+8y-6x+15-4y
=6x+4y+15
=2(3x+2y)+15
=2(-6)+15
=-12+15
=3