解方程 (1)20.52x-(1-0.52)x=80 (2)43x+7=32-2x (3)2(7x-5)=3
问题描述:
解方程 (1)20.52x-(1-0.52)x=80 (2)43x+7=32-2x (3)2(7x-5)=3
(4) 53x+5(138-x)=540
(5)63x-7(x-1)=3-2(x+30
(6)18x+3x-3=18-2(2x-1)
(7)3(20-y)=6y-4(y-11)
(8)4(2x-1)=3(5x+1)
答
(1)20.52x-(1-0.52)x=80
20.52x-0.48x=80
20.04x=80
x=2000/501
(2)43x+7=32-2x
43x+2x=32-7
45x=25
x=5/9
(3)2(7x-5)=3
7x-5=1.5
7x=6.5
x=13/14(4) 53x+5(138-x)=540(5)63x-7(x-1)=3-2(x+30(6)18x+3x-3=18-2(2x-1)(7)3(20-y)=6y-4(y-11)(8)4(2x-1)=3(5x+1)(4) 53x+5(138-x)=54053x+690-5x=54048x=-150x=-25/8(5)63x-7(x-1)=3-2(x+3) 63x-7x+7=3-2x-6 56x+7=-2x-3 58x=-10 x=-5/29(6)18x+3x-3=18-2(2x-1)21x-3=18-4x+225x=23 x=23/25(7)3(20-y)=6y-4(y-11) 60-3y=6y-4y+44 60-3y=2y+44 -5y=-16y=16/5(8)4(2x-1)=3(5x+1)8x-4=15x+3-7x=7 x=-1