Question

解方程: (x+10)+(x-15)=280-x x+15=3*(109-x) 5(3x-1.4)=2(6x-0.5) 3(x+0.9)=5(x-1.7) 13x-4(...

解方程:
(x+10)+(x-15)=280-x
x+15=3*(109-x)
5(3x-1.4)=2(6x-0.5)
3(x+0.9)=5(x-1.7)
13x-4(2x+5)=17(x-2)-4(2x-1)

Answer 1

(x+10)+(x-15)=280-x
2x-5=280-x
3x=285
x=95

x+15=3*(109-x)
x+15=327-3x
4x=312
x=78

5(3x-1.4)=2(6x-0.5)
15x-7=12x-1
3x=6
x=2

3(x+0.9)=5(x-1.7)
3x+2,7=5x-8.5
2x=11.2
x=5.6

13x-4(2x+5)=17(x-2)-4(2x-1)
13x-8x-20=17x-34-8x+4
5x-20=9x-30
4x=10
x=2.5

Answer 2

1.(x+10)+(x-15)=280-x
2x-5=280-x
2x+x=280+5
3x=285
x=95
2.x+15=3*(109-x)
x+15=327-3x
x+3x=327-15
4x=312
x=78
3.5(3x-1.4)=2(6x-0.5)
15x-7=12x-1
15x-12x=7-1
3x=6
x=2
4.3(x+0.9)=5(x-1.7)
3x+2.7=5x-8.5
5x-3x=2.7+8.5
2x=11.2
x=5.6
5.13x-4(2x+5)=17(x-2)-4(2x-1)
13x-8x-20=17x-34-8x+4
13x-17x=-34+4+20
-4x=-10
x=2.5

Answer 3

解方程:
(x+10)+(x-15)=280-x2x-5=280-x3x=285x=93
x+15=3*(109-x)x+15=327-3x4x=312x=78
5(3x-1.4)=2(6x-0.5)15x-7=12x-13x=6x=2
3(x+0.9)=5(x-1.7)3x+2.7=5x-8.52x=11.2x=5.6
13x-4(2x+5)=17(x-2)-4(2x-1)13x-8x-20=17x-34-8x+44x=10x=2.5

Answer 4

第一题：2X-5=280-X
3X=285
X=95

第二题：X+15=327-3X
4X=312
X=78

第三题：15X-7=12X-1
3X=6
X=2
第四题：3X+2.7=5X-8.5
2X=11.2
X=5.6
第五题：13X-8X-20=17X-34-8X+4
5X-20=9X-30
4X=10
X=2.5

Answer 5

x+10+x-15=280-x 2x-5=280-x 3x=285 x=95
x+15=327-3x 4x=312 x=78
15x-7=12x-1 3x=6 x=2
3x+2.7=5x-8.5 11.2=2x x=5.6
13x-8x-20=17x-34-8x+4 10=4x x=2.5