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5 votes
2y+x=-15 and x=3y how to do it

1 Answer

4 votes

Answer:

x= -9, y= -3

Explanation:

I assume that you are asking how to solve the above equations to find the values of x and y.

There are two ways to solve this question.

Firstly, you can solve it by substitution.

For both steps, start off by labeling your equations as equations 1 and 2. The order does not matter.

2y+x= -15 --------(1)

x= 3y ---------(2)

subst. (2) into (1):

2y+ 3y= -15

5y= -15 (simplify to find y)

y= -15/5

y= -3

subst. into (2):

x= 3(-3)

x= -9

We can also solve by elimination.

2y+x= -15 ---------(1)

x= 3y ------------(2)

(1)- (2):

2y+x-x= -15-3y

2y= -15 -3y

2y+3y= -15

5y= -15

y= -3

subst. into (2):

x= 3(-3)

x= -9

Both methods will give you the same answer in the end.

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