Solve the system of linear equations below.

x − 3y = -3
x + 3y = 9

A. x = -12, y = 7

B. x = 3, y = 2

C. x = 6, y = 1

D. x = 6, y = 2

the correct answer is B: x=3, y=2

Step-by-step explanation:

x-3y=-3(1)

x+3y=9(2)

using elimination method.

We eliminate x by introducing subtraction

x-3y=-3

-

x+3y=9

the single equation becomes

0-6y=-12

-6y=-12

Minus cancelled each other

6y=12

y=12/6

y=2

to find x substitute y=2 in equation 1

x-3y=-3

x-3(2)=-3

x-6=-3

x=-3+6

x=3

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.

i’m sorry but i don’t know sorry