Solve the system using elimination 4x-7y=3
x-7y=-15

x=6 and y=3

Step-by-step explanation:

4x - 7y = 3 (1)

x - 7y = -15 (2)

equation(1) - equation (2)

3x = 18

Divide bothside by 3

x = 18/3

x= 6

also, multiply equation (2) by 4

4x - 28y = -60(3)

subtract equation(3) from equation(1)

21y = 63

divide bothside by 21

y = 63/21

y = 3

i think it is everything has to equal 180 so, if i correct 4=c. 6=d. 8=a. 7=b. and the last question would be c. because they are parallel lines and they are congruent.

step-by-step explanation:

the reason everything has to equal to 180 is because that is how it works. i'm guessing that is its rule. 4 and 8 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 6 and 7 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 60+60 is 180. so, now you have your answer