Question

谁帮我解一下这个方程

0.18(x+30)+0.16x+0.2*(70-2x)=18.8
注意，要过程，最后等于10

Answer 1

0.18x+0.18*30+0.16x+0.2*70-0.4x=18.8
(0.18+0.16-0.4)x=18.8-0.18*30-0.2*70
-0.06x=18.8-5.4-14
-0.06x=-0.6
x=10

Answer 2

0.18(x+30)+0.16x+0.2*(70-2x)=18.8
0.18x+0.18*30+0.16x+14-0.4x=18.8
0.18x+0.16x-0.4x+0.18*30+14=18.8
(0.34-4)x=18.8-14-0.18*30
-0.06x=4.8-5.4=-0.6
x=10

Answer 3

0.18(x+30)+0.16x+0.2*(70-2x)=18.8
0.18x+5.4+0.16x+14-0.4x=18.8
(0.18+0.16-0.4)x=18.8-5.4-14
-0.06x=-0.6
x=10

Answer 4

0.18(x+30)+0.16x+0.2*(70-2x)=18.8两边通乘50得
9（x+30)+8x+10(70-2x)=940
9x+270+8x+700-20x=940
-3x=-30
x=10

Answer 5

0.18x+5.4+0.16x+14-0.4x=18.8
0.06x=0.6
x=10