tolong yang jago matematika nomer 3 bagian a,b,c.

a) eliminasi y
x +y = 10
x - y = 2
________-
2x =8
x = 4
sub x =4 ke x-y =2
4-y=2
y=2
(4,2)

b)
x +2y =3
x +3y =4
________-
-y =-1
y =1
x + 2y = 4
x + 2(1)=4
x = 2
(2,1)

c)
2x+y=5 |2| 4x +2y =10
3x- 2y=11 |1| 3x -2y = 11
________+
7x = 21
x = 3
2x +y =5
2( 3) +y = 5
y =-1
( 3,-1)