Question

Solve the system of equations and choose the correct answer from the list of options.

x − y = 7
y = 3x + 12

A: (2/19, 2/33)
B: (-2/19, -33/2)
C: (-19/2, -33/2)
D: (19/2, 33/2)

Answer 1

Since you already have one Y solved, plug that to the other equation "x-y=7" and solve for x. Then after you obtained x plug it on the other equation to get y. You will end up having (x,y) point

Answer 2

ok so... 7=3x+12 then i add seven to both sides right?

Answer 3

x - (3x+12) = 7 <-- this is how it looks after you plug y into the x - y = 7

Answer 4

Ok so i know add three to both sides correct?

Answer 5

now*

Answer 6

@Mateaus

Answer 7

first simplify the left side x-(3x+12)

Answer 8

how would i do that? sorry. im not that good at math

Answer 9

x - (3x + 12)

you need to distribute -1 over the terms in the parentheses
= x -1*3x - 1*12
= x - 3x - 12

Answer 10

first distribute the negative sign before the parenthesis (example: - (2x+3) = -2x-3)

Answer 11

this = 7
so we have
-2x - 12 = 7
solve for x

Answer 12

19/2

Answer 13

-2x = 19
x = -19/2

Answer 14

don't forget to carry on the negative sign :p

Answer 15

-19/2 as you are dividing 19 by -2

Answer 16

ok so the awnswer would be (-19/2,-33/2)?

Answer 17

@Mateaus lol yea

Answer 18

y = x - 7 = -19/2 - 7 = -19/2 - 14/2 = -33/2

Answer 19

well since no other x is -19/2 pretty much yes, that's the answer. Although is a good idea to check the other one as well.

Answer 20

yes - its good for practice to find y

Answer 21

thank yall both for the help even though i was slow :P medal for @Mateaus and can you medal @welshfella for me please if possable