Question

x+2y=70;2x+y=90 in substitution method

Answer 1

given,

x+2y=70

if x=40,

=>40+2y=70

=>2y=30

=>y=15

=>(x,y)=(40,15)

if x=20,

=>20+2y=70

=>2y=50

=>y=25

=>(x,y)=(20,25)

2x+y=90

if x=20,

=>40+y=90

=>y=50

=>(x,y)=(20,50)

if x=40,

=>80+y=90

=>y=10

=>(x,y)=(40,10)

HOPE U UNDERSTAND

PLS MARK IT AS BRAINLIEST

Answer 2

x+2y =70
⇒x= 70-2y-----(1)

2x+y=90----(2)

put (1) in (2)
2(70-2y)+y =90

140 -4y +y =90
-3y = 90-140
-3y = -50

y= (-50)/(-3)
∴y= 50/3

put y value in (1)

x= 70 -2*50/3

x= (210-100)/3
x= 110/3

∴x= 110/3 ,y= 50/3