Question

10% of X + 20% of Y = 24 3x-y= 20

Answer 1

Hi ,

10% of x + 20% of y = 24

=> ( 10/100 )x + ( 20/100 ) y = 24

=> ( 10/100 ) [ x + 2y ] = 24

=> ( 1/10 ) ( x + 2y ) = 24

=> x + 2y = 240 -----( 1 )

3x - y = 20

=> y = 3x - 20 ---( 2 )

Substitute y = 3x - 20 in equation ( 1 )

x + 2( 3x - 20 ) = 240

=> x + 6x - 40 = 240

=> 7x = 240 + 40

=> 7x = 280

x = 280/7

x = 40

Substitute x = 40 in equation ( 2 ),

we get

y = 3 × 40 - 20

y = 120 - 20

y = 100

Therefore ,

x = 40 , y = 100

I hope this helps you.

: )

Answer 2

(10/100)x+(20/100)y=24
(1/10)x+(1/5)y=24
(x/10)+(y/5)=24
2(x+3y/10)=24
x+6y/10=24
x+6y=24×10
x+6y=240
x=240÷6
x=40

It's substitute
3x-y=20
3×40-y=20
120-y=20
-y=20-120
y=100