Solve the system of equations and choose the correct answer from the list of options.
x – y = 7
y = 3x + 12

x=-9.5

y=-16.5

Step-by-step explanation:

Hi, to solve this problem we have to apply the substitution method:

x-y =7 (a)

y=3x+12(b)

Replacing the value of "y" in (a) for (b):

x -(3x+12)=7

x-3x-12=7

x-3x =7+12

-2x =19

x=19/-2

x=-9.5

Replacing the value of "x" in (b)

y=3x+12

y=3(-9.5)+12

y= -28.5+12

y=-16.5

Feel free to ask for more if needed or if you did not understand something.

answer: can and shows the work

step-by-step explanation:

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation: