用加减法解方程组:1、x+1/3=y+2/4 4x+3y=14
1个回答

(1)(x+1)/3=(y+2)/4通分4(x+1)=3(y+2)整理得(3)4x-3y=2

(2) 4x+3y=14与(2)相减

6y=12

y=2 代入到(2)

4x=14-3y=8

x=2

(1)x+y/3+x-y/2=6

(2)3(x+y)-2(x-y)=28

(1)(x+y )/3 + (x-y)/2=6 通分2(x+y)+3(x-y)=36——2x+2y+3x-3y=36整理得(3)

(2)3(x+y)-2(x-y)=28——3x+3y-2x+2y=28 整理得(4) x+5y=28

(3)5x-y=36 两边×5得(5)

(5)25x-5y=180 与(4)相加

26x=208

x=8 代入到(3)

y=5x-36=40-36=4