解答題2x-7y=3,4x+2y=-2

解答題2x-7y=3,4x+2y=-2


2x-7y=3(1)
4x+2y=-2(2)
(1)×2 4x-14y=6(3)
(2)-(3)16y=-8
y=-½;
代入(1)2x+3.5=3
x=-¼;
∴{x=-¼;,y=-½;是原方程組的解



10y-2(7y-2)=5(4y+5)


10y-2(7y-2)=5(4y+5)
10y-14y+4=20y+25
10y-14y-20y=25-4
-24y=21
y=-21/24
y=-7/8



1/3(3y-(10-7y)/2)-1/2(2y-(2y+2/3)=y/2-1內含分數


Y-(10-7Y)/6-Y+(Y+1/3)=Y/2-1
6Y-10+7Y-6Y+6Y+2=3Y-6
10Y=2
Y=1/5.