Question

3x-4y=20 and x+2y=5 it is of class 10 chapter is linear equation in two variable

Answer 1

3x-4y=20 ---(1)
x+2y=5 ---(2)
From (2),
x=5-2y
Putting the value of x in (1),
3(5-2y) - 4y = 20
or, 15 - 6y - 4y = 20
or, 15 - 10y = 20
or, 10y = -5
or, y = -0.5

x= 5 - 2y
or x= 5+1=6
x=6, y= -0.5

HOPE THIS HELPS! Thanks!

Answer 2

3x-4y=20.....consider it equation...ist and x+2y=5......equation second... now we will find the value of x and y by substitution method or any other ....let it be substitution method ......so....from equation ist 3x=20-4y
x=20-4y/3......=n....3rd now substitute the value of x in equation 2nd I .e 20-4y/3+2y=5
20-4y+6y =15
20+2y=15
2y=15-20
2y=-5
y=-5/2
......now substitute the value of y in equation 3rd I.e
20-4 (-5/2)/3
I.e the value of x