Question

Need help with solving 4x-y=9, x-3y=16?

Answer 1

put value of y from eq. 1 to eq. 2

we have

x - 3(4x-9)=16

x-12x+27=16

-11x = -11

x=1

put in any eq. we get y= -5

Answer 2

Given ,

4x-y=9 ...(1)

x-3y=16 ...(2)

Multiplying 4 to equation (2),

we get ,

4x-12y=64 ...(3)

Now ,

Substracting equation (3) and (1), we get ,

4x-y=9

4x-12y=64

- + -

____________

11y = -55

y = -5

Putting value in equation (1)

We get ,

4x-y=9

4x-(-5)=9

4x+5=9

4x=9-5

4x=4

x=1

Answer :-

x=1

y=-5