Question

4x+7y=13 3x+5y=9 by substitution method

Answer 1

4x+7y=13........(1)
3x+5y=9.........(2)

now, in equation one

4x+7y=13
4x=13-7y
x=(13-7y)×1÷4

Now putting value of x in equation 2
we get,

3×(13-7y)×1÷4 +5y=9

(39-21y)×1÷4 +5y=9

(39-21y+20y)×1÷4=9
39-1y=36
-y=36-38
-y=-3
y=3

now putting the value of y in equation 2
we get,

3x+5×3=9
3x=9-15
x=-6÷3
x=-2