Question

Find the solutions to these equations. I suggest using a graph. Thank you for helping!

-3x - 9y=18


4x+3y=12

Answer 1

The value of x is 6 and The value of y is - 4

Explanation:

Given as :

The Two linear equation is

- 3 x - 9 y = 18

4 x + 3 y = 12

Now,

4 × ( - 3 x - 9 y ) = 4 × 18

Or, - 12 x - 36 y = 72 ......1

And 3 × ( 4 x + 3 y ) = 3 × 12

or, 12 x + 9 y = 36 .....2

Solving eq 1 and 2

( 12 x + 9 y ) + ( - 12 x - 36 y ) = 72 + 36

Or, 9 y - 36 y = 108

or , 27 y = - 108

∴ y = -
`(108)/(27)`

I.e y = - 4

Put the value of y to get x value

So, 12 x + 9 (-4) = 36

Or, 12 x = 36 + 36

or, 12 x = 72

∴ x =
`(72)/(12)`

I.e x = 6

Hence The value of x is 6 and The value of y is - 4 Answer