Question

解方程2X-1.8=X+2.4 3X-2(10-X)=15 (2X+3)*2=5X-4 18/4X-3=9 (4-X)*7=(X-4)*9 6.2*(3X-4)+7*(4-X)=4X

求求大家

Answer 1

2X-1.8=X+2.4
2x-x=2.4+1.8
x=4.2

3X-2(10-X)=15
3x-20+2x=15
5x=35
x=7

(2X+3)*2=5X-4
4x+6=5x-4
5x-4x=6+4
x=10

18/4X-3=9
18/4x=12
x=8/3

(4-X)*7=(X-4)*9
28-7x=9x-36
9x+7x=28+36
16x=64
x=4

6.2*(3X-4)+7*(4-X)=4X
18.6x-24.8+28-7x=4x
18.6x-7x-4x=24.8-28
7.6x=-3.2
x=-8/19

Answer 2

2X-1.8=X+2.4
2X-X=2.4+1.8
X=4.2

3X-2(10-X)=15
3X-20+2X=15
5X=15+20
5X=35
X=7

(2X+3)*2=5X-4
4X+6=5X-4
6+4=5X-4X
X-10

18/4X-3=9
18/4X=9+3
18/4X=12
X=12* 4/18
X=4/3

(4-X)*7=(X-4)*9
28-7X=9X-36
28+36=9X+7X
64=16X
X=4

6.2*(3X-4)+7*(4-X)=4X
18.6X-24.8+28-7X=4X
18.6X-7X-4X=24.8-28
7.6X=-3.2
X=- 3.2/7.6

X=- 8/19