Question

x²+2y²=3,2x-3y=5

（1）｛x+2y=4①,2x-y=3②
（2）｛3x-4y=19①,x+2y=3②
（3）｛3x-2y=7①,2分之x+3-y=0②
（4）｛x-2y=1①,2x+3y=16②
(5)｛ 4s+3t=5①,2s-t=-5②
(6)｛2x+5y=12①,2x+3y=6②
(7)｛2a-3b=4①,a/2+b/2=1②
(8)｛x-2=2(y-1)①,2(x-2)+y-1=5②

Answer 1

x+2y=4 2x-y=3 y=2x-3
x+2(2x-3)=4 x=2 y=1
2 3x-4y=19 x+2y=3 x=3-2y
3(3-2y)-4y=19 y=-1 x=5
3 3x-2y=7 (x+3)/2-y=0 y=(x+3)/2
3x-2(x+3)/2=7 x=5 y=4
4 x-2y=1 2x+3y=16 x=1+2y
4y+2+3y=16 y=2 x=5
5 4s+3t=5 2s-t=-5 t=2s+5
4s+3(2s+5)=5 s=-1 t=3
6 2x+5y=12 2x+3y=6 2x=6-3y
6-3y+5y=12 y=3 x=-3/2
7 2a-3b=4 a/2+b/2=1 a=2-b
2(2-b)-3b=4 b=0 a=2
8 x-2=2(y-1) 2(x-2)+y-1=5 x=2+2(y-1)
4(y-1)+y-1=5 y=2 x=4