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Directions: Use system of linear equations

9x-3y=-1

1/5x+2/5y=-1/3

User Cetcet
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1 Answer

1 vote

Answer:

The solution to this set of linear equations is:


x=-(1)/(3)\\y=-(2)/(3)

Step-by-step explanation:

This is a system of two equations with two unknown variables x and y, let's call them

Equation 1:
9x-3y=-1

Equation 2:
(1)/(5)x+(2)/(5)y=-(1)/(3)

The first step is to solve Equation 1 for y, this means to leave the y alone on one side of the equal


y= 3x+(1)/(3)

Then with this equation, you can find the value of x by replacing y in Equation 2


(1)/(5)x+(2)/(5)(3x+(1)/(3))=-(1)/(3)

Then simplify this equation to find x


(1)/(5)x+(6)/(5)x+(2)/(15)=-(1)/(3)


(1)/(5)x+(6)/(5)x=-(1)/(3)-(2)/(15)


(7)/(5)x=-(5)/(15)-(2)/(15)


(7)/(5)x=-(7)/(15)

Now you solve for x


x=-(1)/(3)

Now you use this value of x to find y


y=3(-(1)/(3))+(1)/(3)\\y=-(2)/(3)

You can check if this answer is correct by replacing the values of x and y into Equation 1 or 2, in this case, let's take Equation 1:


9(-(1)/(3))-3(-(2)/(3))=-1\\-3+2=-1\\-1=-1\\

User Maxim Alexeyev
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