Question

Solve the system by substitution. 4x=8y 2x+5y=27

Answer 1

`(6,3)`

Explanation:

`4x = 8y\\4x/4 = x\\8y/4= 2y\\x=2y`

`2(2y)+5y=27\\4y+5y=27\\9y=27\\9y/9=y\\27/9=3\\y=3`

`x =2y\\x= 2(3)\\x=6`

Answer 2

(6, 3)

General Formulas and Concepts:

Pre-Alg

• Order of Operations: BPEMDAS

Alg I

• Solving systems of equations using substitution/elimination

Explanation:

Step 1: Define systems

4x = 8y

2x + 5y = 27

Step 2: Rewrite systems

x = 2y

2x + 5y = 27

Step 3: Solve for y

1. Substitute: 2(2y) + 5y = 27
2. Multiply: 4y + 5y = 27
3. Combine like terms: 9y = 27
4. Isolate y: y = 3

Step 4: Solve for x

Plug in y into an original equation to find x.

1. Substitute: 4x = 8(3)
2. Multiply: 4x = 24
3. Isolate x: x = 6