5x+4y=-14
3x+6y=6
solve the system below by the elimation

y = 4

x = -6

Step-by-step explanation:

multiply first equation by 3

3×(5x+4y)= -14 ➡ 15x + 12y = -42

multiply second equation by -5

-5×(3x+6y)= 6➡ -15x -30y = -30

now add both equations up

15x +12y -15x -30y = -42 -30 (15x will eliminate -15x)

-18y = -72

y = 4 use this to find value of x

3x + 6×4 = 6 ➡ ex = -18 ➡ x = -6

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

12cm

the answer is d