设乙家度数为x.甲家度数为y.
0.5(50-x)+0.45(y-50)=2.8
25-0.5x+0.45y-22.5=2.8
5-x+0.9y=5.6
x+0.6=0.9y
x=48 y=54
48×0.5=24(乙) 24+2.8=26.8(甲)
设乙家度数为x.甲家度数为y.
0.5(50-x)+0.45(y-50)=2.8
25-0.5x+0.45y-22.5=2.8
5-x+0.9y=5.6
x+0.6=0.9y
x=48 y=54
48×0.5=24(乙) 24+2.8=26.8(甲)