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4 votes
4x-y=-3 + 5x+y=21 how do I find the answer

User Napuzba
by
7.9k points

2 Answers

6 votes

Answer:

Solution = (2, 11)

Step-by-step explanation:

Step-by-step explanation:

In this question, they want you to solve a system of equations by addition. Because we already have two variables with opposite signs, we can add them together and solve for x.

Step 1: Add the two equations together

1. 4x + 5x - y + y = -3 + 21

Step 2: Simplify

2. 4x + 5x - y + y = -3 + 21 → 4x + 5x = 18 → 9x = 18

Step 3: Solve for x

3. 9x = 18 → x = 2

Step 4: Substitute 2 for x in either one of the original equations

4. 4(2) - y = -3

Step 5: Solve for y

5. 8 - y = -3 → -y = -11 → y = 11

Solution = (2, 11)

Hope this helps you out :)

User Matphy
by
9.1k points
4 votes

Answer:

x=2

y=11

Step-by-step explanation:

4x-y=3

+y +y

4x=-3+y

+3 +3

4x+3=y

5x+4x+3=21

9x+3=21

-3. -3

9x=18

/9. /9

x=2

4(2)-y= -3

8-y= -3

-8. -8

-y= -11

/-1 /-1

y=11

hopes this helps

User Right Of Zen
by
8.2k points

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