Question

PLEASE HELP! :D
which graph represents the solution to the given systems? -4x+2y=-11 and -2x+2y=-15

Answer 1

@whpalmer4

Answer 2

Try putting x=0 and y=0 to the two equations to find the x- and y-intercepts. You should be able to eliminate some choices by that.

Answer 3

not B or D???

Answer 4

@superdavesuper makes a good suggestion: put in x = 0 to find the y-intercepts, and y=0 to find the x-intercepts.

Answer 5

OK then check the slopes of the two equations to find the only valid answer...

Answer 6

lol @whpalmer4 i was expecting u to show the steps in solving the equations :P

Answer 7

having ruled out two choices (B&D), you can move on to trying the intersection point in the equations to see which works. by the way, graphs a and c appear to be identical to me...

Answer 8

sorry, I misinterpreted what you guys said — I'm not ruling out B&D

Answer 9

@superdavesuper probably that's what I would in fact do with these two equations, yes :-)

Answer 10

Ya since a and c are the same it must be B or D.

Answer 11

but I'm a big fan of plugging in 0 wherever it might yield a quick answer!

Answer 12

but are graphs a and c supposed to be identical?!?

Answer 13

I don't know? It looks like it to me?

Answer 14

ooops...sorry @amandaaa00rouseee whpalmer4 is right - i didnt check on B & D when u said they were out....u should check them again...

Answer 15

is it D?

Answer 16

D intersects at x=-2, y=-9.5
Let's check if those values work:

\[-4x+2y=-11\]\[-4(-2)+2(-9.5)=-11\]\[8-19=-11\checkmark\]
\[-2x+2y=-15\]\[-2(-2)+2(-9.5)=-15\]\[4-19=-15\checkmark\]

Answer 17

both lines go through that point, so it is the correct answer

Answer 18

Okay. Thanks. :)

Answer 19

I asked about a&c because usually multiple choice questions don't have 2 identical answers, and wasn't sure if you possibly copied the wrong graph or something

Answer 20

They show they are the same on the problem.

Answer 21

and we found an answer which is 100% correct, so it appears that a&c don't matter.

Answer 22

I'm just naturally suspicious :-)

Answer 23

Nope I will tell them that there are 2 identical answers.

Answer 24

Sorry I got tied up elsewhere. my cheesy way of solving this would be check the intercepts n rule out A & C; then check slopes (both are +ve) to rule out B. Then the only possible answer is D :)

Answer 25

Here's how I would have solved it:

\[-4x+2y=-11\]\[-2x+2y=-15\]Subtract the second equation from the first:
\[-4x-(-2x)+2y-2y=-11-(-15)\]\[-2x+0y=4\]\[x=-2\]Plug into previous equation and solve for \(y\)\[-2(-2) + 2y = -15\]\[4+2y=-15\]\[2y=-19\]\[y=-\frac{19}{2}=-9.5\]

Answer 26

I only got as far as checking the x intercepts, then noticed the coefficients made for an easy solution :-)

Answer 27

Thanks!

Answer 28

actually @amandaaa00rouseee 's statement about A & C being the same is also valid - they cannot be the right answer as they are the same :)

Answer 29

An excellent point, and true so long as no mistake was made in transmitting the problem!

Many ways to solve problems, pays to keep an open mind and learn from others!

Answer 30

I learn something new here just about every day...

Answer 31

mee 2!

Answer 32

Now I just have 9 more questions to do. lol!

Answer 33

Joe wants to put a rectangular pen for his goats. The length of the pen should be at least 60 ft, and the distance around should be no more than 260 ft. Which system of inequalities and graph represent the possible dimensions of the pen?

Answer 34

A few keywords to note in the Q "AT LEAST 60ft" so that means the length must be...

Then "no more than 260ft" which means distance around i.e. perimeter must be...

See if u can go on from here :)

Answer 35

A?

Answer 36

:) hahahaa u ARE good, Amanda!

Answer 37

Thanks. :)