-5x+4y=-30 6x-2y=43 need help?

- 5 x + 4 y = - 30
12 x - 4 y = 86------Add

7x = 56
x = 8

- 40 + 4 y = - 30
4 y = 10
y = 2.5

x = 8 , y = 2.5

Solve by using substitution.

-5x + 4y = -30
6x - 2y = 43

6x - 2y = 43
2y = 6x - 43
y = (6x - 43)/2
y = 6x/2 - 43/2
y = (3x - 43/2) ...... (1)

-5x + 4y = -30

Substitute (1) for y.
-5x + 4(3x - 43/2) = -30
-5x + 4(3x) - 2(43) = -30
-5x + 12x - 86 = -30
7x = 86 - 30
x = 56/7
x = 8

-5x + 4y = -30

Substitute 8 for x.
-5(8) + 4y = -30
-40 + 4y = -30
4y = 40 - 30
y = 10/4
y = 5/2 (2.5)

Hence x = 8 and y = 5/2 (2.5).

1) Set up the two equations as a system

-5x+4y=-30
6x-2y=43

2)Solve the equation by elimination.

-5x+4y=-30
2(6x-2y=43)

-5x+4y=-30
12x-4y=86

7x= 56

x=8

3) now plug 8 for x into the two equations to find the value of y.

-5(8)+4y=-30
6(8)-2y= 43

y=2.5


4) The answer is x=8 and y=2.5

Do you want me to find x and y?