Question

((looking to understand this, not get a direct answer!))
What is the solution of the system?
2x-y+-7
4x-y=-4

A. (-1.5,4)
B. (1.5, 10)
C. (4, -1.5)
D. (-1.5,-2)
((any help is appreciated, thank you!))

Answer 1

i would multiply the first equation by -2 so you add them both up and use elimination to solve.

2x-y=-7
4x-y=-4

-4x+2y=14
4x-y=-4

Answer 2

what do you get for y?

Answer 3

wow once you get y you don't even need to solve for x

Answer 4

I don't know what y is

Answer 5

-4x+2y=14
4x-y=-4

all you have to do is add these 2 up like its normal addition

Answer 6

get it?

Answer 7

getting it so far, yes

Answer 8

so add them up to get y lol

Answer 9

-4x+2y=14
4x-y=-4

-4x+4x=0
2y+(-y)=y
14+(-4)=10

therefore y=?

Answer 10

hold on hold on lemme solve this. I'm slow with math, pft. Gimme a bit.

Answer 11

haha it's really easy i think you just don't see it

Answer 12

yeah, I'm probably just not getting it at all...

Answer 13

to solve these problems you need to isolate a variable. that's why i multiplied the first one by -2 so that the -4x and 4x will cross out once you add it

Answer 14

I still don't get it. Sorry.

Answer 15

uhh

Answer 16

2x-y+=7
4x-y=-4

the absolute easiest way your gonna solve this is to plug these both into the calculator and see where the 2 lines intersect

Answer 17

A. (-1.5,4) B. (1.5, 10) C. (4, -1.5) D. (-1.5,-2)

or you can plug these points in one by one to

2x-y+=7

4x-y=-4

with the appropriate x and y coordinates

Answer 18

personally i think algebraic elimination or substitution is the easiest which is what I tried to show you at first. what are you not understanding?

Answer 19

Alright I have a calculator now. I know it's not A, so far.

Answer 20

alright, solve it with a calculator for now. but do attempt to learn the algebraic methods eventually as some tests may not allow a calculator .

Answer 21

True true. Eliminated B as well. Thank you for this help.

Answer 22

I got C.

Answer 23

actually it's not C lol

Answer 24

Alright then, I'll redo my math for the other three :/

Answer 25

what does the intersection say lol

Answer 26

... B

Answer 27

yep

Answer 28

I wasn't using a graphing calculator I don't have one, so I was just using a normal one

Answer 29

Thank you for the help, haha... Sorry for going in circles with this problem.

Answer 30

np. good effort