用代入法解方程组
(1){a=2b+3 (2){x-y=13 (3){x-y=4 (4){5x-y=110
{a=3b+20 {x=6y-7 {4x+2y=-1 {9y-x=110
回答~最好也说明理由~
如何运用?
(1){a=2b+3 (2){x-y=13 (3){x-y=4 (4){5x-y=110
(1){a=3b+20 (2){x=6y-7 (3){4x+2y=-1 (4){9y-x=110
回答~最好也说明理由~
如何运用?