问题 解答题
甲、乙两人解方程组
ax+5y=13①
4x-by=-2②
,由于甲看错了方程①中的a而得到方程组的解为
x=-3
y=-1
,乙看错了方程②中的b而得到的解为
x=5
y=4
,假如按正确的a,b计算,试求出原方程的解.
答案

因为甲只看错了方程①中的a,所以甲所得到的解为

x=-3
y=-1

应满足无a的正确的方程②,即4×(-3)-b×(-1)=-2.③

同理,

x=5
y=4
,应满足正确的方程①,即a×5+5×4=13.④

解由③,④联立的方程组得:

a= -
7
5
b=10

∴原方程组应为:

-
7
5
x+5y=13
4x-10y=-2

解得:

x=20
y=
41
5

阅读理解

阅读理解。

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判断题