Question

解下列方程： (1)4/3-8x=3-11/2x; (2)0.5x-0.7=6.5-1.3x; (3)1/6(3x-6)=2/5x-3; (4)1-2x/3=3x+1/7-3;

当x为何值时,下列各组中两个式子的值相等?
(1)x-(x-1)和7-（x+3)/5;
(2)2/5x+(x-1)/2和3(x-1)/2-8/5x
在梯形面积公式S=1/2(a+b)h中
(1)已知S=30,a=6,h=4,求b;
(2)已知S=60,b=4,h=21,求a;
(3)已知S=50,a=6,b=5/3a,求h;

求解, 速度, 列式+答案 谢谢`

Answer 1

x-(x-1)=7-(x+3)/5
x-x+1=7-x/5+3/5
x/5=7-3/5-1
x/5=27/5
x=27.
只是第一题的解，后面自己想吧
..

Answer 2

(1)X=-2/3;
(2)X=9;
(3)X=20;
(2)X=-81/77;

Answer 3

(0.5+1.3)x=6.5+0.7
1.8x=7.2
x=4