Question

5x+y=9 10x-7y=-8 I need help!

Answer 1

Answer:

(11/9, 26/9)

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right  

Equality Properties

• Multiplication Property of Equality
• Division Property of Equality
• Addition Property of Equality
• Subtract Property of Equality

Algebra I

• Terms/Coefficients
• Solving systems of equations using substitution/elimination

Step-by-step explanation:

Step 1: Define Systems

5x + y = 9

10x - 7y = -8

Step 2: Rewrite Systems

Manipulating: Equation 5x + y = 9

1. Subtract 5x on both sides:                    y = 9 - 5x

Step 3: Redefine Systems

y = 9 - 5x

10x - 7y = -8

Step 4: Solve for x

Substitution

1. Substitute in x:                    10x - 7(9 - 5x) = -8
2. Distribute -7:                        10x - 63 + 35x = -8
3. Combine like terms:           45x - 63 = -8
4. Add 63 on both sides:        45x = 55
5. Divide 45 on both sides:    x = 11/9

Step 5: Solve for y

1. Define equation:                    5x + y = 9
2. Substitute in x:                       5(11/9) + y = 9
3. Multiply:                                  55/9 + y = 9
4. Isolate y:                                 y = 26/9