Question

10x+5y=30 and 20x+5y=50 solve by substitution

Answer 1

x = 3 - y/2 that’s for the 1st answer

Answer 2

10x+5y=30
20x+5y=50

20x+5y=50
5y=-20x+50 ( divided by 5 )
y=-4x+10

10x+5y=30
10x+5(-4x+10 ) =30 ( substitute Y value )
10x-20x+50=30
-10x=-20
x=2
20x+5y=50
20(2)+5y=50
40+5y=50
5y=10
y=2

( 2, 2 )