两道数学题!
解方程组{(x+1)/3 = (y+1)/2 +1/6{2/3 x+ 1/2y=5/3 (有过程){x+y+42{1.008x+1.011y=42.42 (可无)
参考答案:解:(1){x/3-y/2=1/3
{2/3x+1/2y=5/3
两式想加得x=2 y=2/3
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(2)由题意{x+y=42 (1)
{1.008x+1.011y=42.42 (2)
得(2)-(1)得
0.008x+0.011y=0.42
即8x+11y=420 (3)
(3)-(1)*8得
3y=84
得y=28 x=14