Question

solve by elimination 3x+y=5 -2x-y=-10

Answer 1

Answer:

(-5, 20)

General Formulas and Concepts:

Pre-Algebra

• Order of Operations: BPEMDAS
• Equality Properties

Algebra I

• Solving systems of equations using substitution/elimination
• Solving systems of equations by graphing

Step-by-step explanation:

Step 1: Define systems

3x + y = 5

-2x - y = -10

Step 2: Solve for x

Elimination

1. Add 2 equations together:                    x = -5

Step 3: Solve for y

1. Define original equation:                    3x + y = 5
2. Substitute in x:                                     3(-5) + y = 5
3. Multiply:                                                -15 + y = 5
4. Add 15 on both sides:                          y = 20

Step 4: Graph systems

Check the solution set and graph.

Answer 2

Answer:

x = -5

y = 20

Step-by-step explanation:

3x + y = 5 ⇒ y = 5 - 3x

-2x - y = -10 ⇒ 2x + y = 10

2x + (5 - 3x) = 10

5 - x = 10

x = -5

Substitution of x-value into "y = 5 - 3x":

y = 5  - 3(-5)

y = 5 + 15

y = 20