Question

У = 12 - 4x
| 5x - Зу = -2
Solve the system algebraically

Answer 1

x = 2

y = 4

Explanation:

y = 12 - 4x ⇒ ( 1 )

5x - 3y = -2 ⇒ ( 2 )

Let us find the value of x.

For that, take equation (2) and replace y with ( 12 - 4x ).

5x - 3y = -2

5x - 3 ( 12 - 4x ) = -2

5x - 36 + 12x = -2

Combine like terms.

17x - 36 = -2

Add 36 to both sides.

17x = -2 + 36

17x = 34

Divide both sides by 17.

x = 2

Let us find the value of y.

To find the value of y let us take equation ( 1 ) and replace x with 2.

y = 12 - 4 × 2

y = 12 - 8

y = 4

Answer 2

x = 2

Explanation:

у = 12 - 4x

5x - Зу = -2

Solve the system algebraically.

Substitute the first equation into the second equation.

5x - 3( 12 - 4x) =-2

Distribute.

5x - 36 + 12x = -2

Combine like terms.

17x -36 = -2

Add 36 to each side

17x -36+26 = -2+36

17x = 24

Divide by 17

17x/17 = 34/17

x = 2