Question

Consider the following system of equations. Solve and write as a coordinate point.

5x+4y=-14
3x+6y=6

Please help and thanks

Answer 1

You have to decide which variable to eliminate.

Lets choose x. We need the coefficients to be equal and opposite. I will multiply the first equation by 3 and the second equation by -5

15x + 12y =42
-15x -30y = -30

Add the two equations and the x will be eliminated.

-18y = 12 y = -12/18 = -2/3

To find x - replace y with the answer. I will choose the second equation because it seems easier.

3x + 6(-2/3) = 6

3x -4 = 6
3x = 10
x = 10/3

(10/3, -2/3)

Check in both equation to be sure that a mistake hasn't been made.

Answer 2

well, I think I would multiply the first one by three and the second one by two

15 x + 12 y = -42
6 x + 12 y = 12
------------------ subtract
9 x = -54 or x = -6
then
-18 + 6 y = 6
6 y = 24
y = 4


(-6 , 4 )

Answer 3

John's error, after multiplying by 3 , should be

15x + 12y = -42 , John had +42