woaini515
幼苗
共回答了12个问题采纳率:91.7% 举报
(6)1/2(x-1)-1/5(x+2)=1/3x-1
解 两边乘以30得15(x-1)-6(x+2)=10x-30,
15x-15-6x-12=10x-30,
x=3.
(7)3[5x-4(2-x)]-7=5
解3[5x-8+4x]=12,
9x-8=4,
9x=12,
x=4/3.
(8)1/3[1/4(1/5x-1)-6]+4=2
解 (1/4)(x/5-1)-6+12=6,
(1/4)(x/5-1)=0,
x/5=1,
x=5.
(9)(3/4)[(4/3)(x/2-1)+8]=(3/2)x+1,
解 x/2-1+6=(3/2)x+1,
x=4.
1年前
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