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Solve for the following system of equations. -7x+6y=9 -2x-5y=16 x=? y=?

User Kirgy
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2 Answers

1 vote

Answer:

Step-by-step explanation: You are given the equation of -7x+6y=9 and -2x-5y=16 and you are asked to find what x=? and what y=?

First step is to write down the problem

-2x-5y=16

next add 5y over the equal sign.

-2x=5y+16

Next is too divide by -2

-2x/-2=5y+16/-2

after solving you get

x=-2.5y-8

now you substitute the equation into the other formula to get

-7(-2.5y-8)+6y=9

then solve by doing -7*-2.5y and -7*-8 to get 17.5y and 56 which will give you

17.5y+56+6y=9

Next you subtract 56 to the other side to get 9-56 or -47 now you have

17.5y+6y=-47

next is too add the 17.5y and 6y together to get 23.5y

23.5y=-47

next is too divide by 23.5

23.5y/23.5=-47/23.5

solve to get y=-2, now this is half you the problem

Step two is too substitute what y=-2 into the equation of x=-2.5y-8 to get

x=-2.5(-2)-8

Solve to get

x=5-8

Solve again to get

x=-3

Your answers are x=-3 and y=-2

User Fokko Driesprong
by
5.2k points
5 votes

Answer:

x = -3 and y = -2

Explanation:

It is given that,

-7x + 6y = 9

----(1)

-2x - 5y = 16 -------(2)

To find the solution of given equations

eq(1) * 2 ⇒

-14x + 12y = 18 ------(3)

eq(2) * 7 ⇒

-14x - 35y = 112 ---(4)

eq (3) - eq(4) ⇒

-14x + 12y = 18 ------(3)

-14x - 35y = 112 ---(4)

0 4y = -94

y = 94/(-47) = -2

Substitute the value of y in eq (2)

-2x - 5y = 16 -------(2)

-2x - 5*-2 = 16

-2x +10 = 16

-2x = 6

x = 6/-2 = -3

Therefore x = -3 and y = -2

User Weiji
by
4.9k points