Question

CAN SOMEONE PLEASE HELP ME?! WILL GIVE MEDAL!
Which ordered pair is the solution to the system of equations?
https://static.k12.com/bank_packages/files/media/mathml_528dd1cc4ef253591f2fd9cf7abf1149de26b351_1.gif


A.
(2, 2)

B.
(1, −7)

C.
(−1, 5)

D.
(−2, 4)

Answer 1

x+y=4 <---equation 1
x-y=-6 <---equation 2
Let's use the subsittuion method :-)
Let's start by isolating equation 1 for y any ideas on what to do first ?

Answer 2

not really sorry...
@pooja195

Answer 3

It's alright isolating means to seperate something to make it stand alone in this case to sperate y we would simply subtract x from both sides
like this:
\[\huge~\rm~\bf~x-x+y=4-x\]
Now we have
\[\huge~\rm~\bf~y=-x+4\]
That is our new equation 1
y=-x+4 <---equation 1
x-y=-6 <---equation 2
since we know the value of y we can plug it into equation 2
\[\huge~\rm~x-(-x+4)=-6\]
solve for x

Answer 4

x=-5???? @pooja195

Answer 5

Let's do that step by step....-5 is incorrect
When we have 2 negative signs together they become a positive.
x+x+4=-6
next step subtract 4 from both sides
4-4=0
-6-4= ?

Answer 6

-10

Answer 7

@pooja195

Answer 8

Hold up this was done wrong
the "-" serves as -1
So we have this

(x+x)+(−4)=−6(Combine Like Terms)
2x-4=-6
now we ADD for not subtract
-6+4=?

Answer 9

-2 @pooja195

Answer 10

Good combine the 2x's and get 2x
2x=-2/2
divide both sides by 2
2/2=x(1)
x=?

Answer 11

1?????? @pooja195

Answer 12

- divded by a pos=-
so -1
take -1 plug it in play of x in equation 1
You dont even need to do that because only one of your answer choices contains -1 as the x value