解二元一次方程组5x+2y=40(1)6.25x+2.4y=48.2(2)

问题描述:

解二元一次方程组5x+2y=40(1)6.25x+2.4y=48.2(2)

5x+2y=40(1)6.25x+2.4y=48.2 ( 2)625x+240y=4820125x+48y=964 (3) (1)x25,得,125x+50y=1000 (4)(4)-(3),得,2y=36,y=18代入(1)5x+36=40,x=4/5=0.8所以,二元一次方程组的x=0.8,y=18