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Solve the system of linear equations. 3x + y = 9 y − 2x = 4 A) (1, 6) B) (−1, 6) C) (1, −6) D) (−1, −6)

User Ahj
by
4.2k points

2 Answers

7 votes

Answer:


\boxed{OptionA}

Explanation:

3x+y = 9

y-2x = 4

Subtracting both equations

=> 3x+y-(y-2x) = 9-4

=> 3x+y-y+2x = 5

=> 3x+2x = 5

=> 5x = 5

Dividing both sides by 5

=> x = 1

Now, Putting x = 1 in the first equation

=> 3(1)+y = 9

=> 3+y = 9

=> y = 9-3

=> y = 6

Ordered pair = (x,y) = (1,6)

User David Van Staden
by
3.6k points
6 votes

Hey there! :)

Answer:

A) (1, 6)

Explanation:

Solve by setting both equations equal to each other. Begin by rearranging each equation to equal y:

3x + y = 9

y = -3x + 9

--------------

y - 2x = 4

y = 2x + 4

---------------

-3x + 9 = 2x + 4

Add 3x to both sides:

-3x + 3x + 9 = 2x + 3x + 4

9 = 5x + 4

Subtract 4 from both sides:

9 - 4 = 5x + 4 - 4

5 = 5x

Divide both sides by 5:

5/5 = 5x/5

x = 1. Substitute 1 into an equation to solve for y:

3(1) + y = 9

3 + y = 9

y = 9 - 3

y = 6.

Therefore, the coordinates of the solution are:

A) (1, 6)

User Manuel Selva
by
4.5k points