2x-4+x=11 3.8/x-1.3=3.7 8.3-0.6x=0.5 2.8X-3.12=39.02 解方程
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2x-4+x=11 3.8/x-1.3=3.7 8.3-0.6x=0.5 2.8X-3.12=39.02 解方程
2x-4+x=11 3.8/x-1.3=3.7 8.3-0.6x=0.5 2.8X-3.12=39.02 解方程
2x-4+x=11 3.8/x-1.3=3.7 8.3-0.6x=0.5 2.8X-3.12=39.02 解方程
2x-4+x=11
3x=11+4
x=5
3.8/x-1.3=3.7
3.8/x=5
5x=3.8
x=0.76
8.3-0.6x=0.5
8.3-0.5=0.6x
0.6x=7.8
x=13
2.8X-3.12=39.02
2.8x=42.14
x=15.05
X=5 X=0.76 X=13 X= 15.05
1) 2x-4+x=11 ==> 2x -4 + x + 4 = 11 + 4 ==> 3x = 15 ==> x=5;
2) 3.8/x-1.3=3.7 ==> 3.8/x -1.3 + 1.3 = 3.7 + 1.3 ==> 3.8/x=5 ==> x=0.76;
3) 8.3-0.6x=0.5 ==> 8.3-0.6x-0.5=0.5-0.5 ==> 7.8=0.6x ==>...
全部展开
1) 2x-4+x=11 ==> 2x -4 + x + 4 = 11 + 4 ==> 3x = 15 ==> x=5;
2) 3.8/x-1.3=3.7 ==> 3.8/x -1.3 + 1.3 = 3.7 + 1.3 ==> 3.8/x=5 ==> x=0.76;
3) 8.3-0.6x=0.5 ==> 8.3-0.6x-0.5=0.5-0.5 ==> 7.8=0.6x ==> x=13;
4) 2.8X-3.12=39.02 ==> 2.8X=39.02+3.12=42.14 ==> x=42.14/2.8 = 15.05;
一元一次方程,不会是小朋友的家庭作业吧。。。
收起
去括号,得:2x2+x=8x-3,
移项,得:2x2+x-8x+3=0
合并同类项,得:2x2-7x+3=0,
∴(2x-1)(x-3)=0,
∴2x-1=0或 x-3=0,
∴x1=
12,x2=3.