Question

Which is the most efficient method substitution or elimination or graphing to solve the system of equation. Explain why the method you pick is the is the most efficient. 5x + 3y = 6 and -4x -3y = -3

Answer 1

see explanation

Explanation:

5x + 3y = 6 → (1)

- 4x - 3y = - 3 → (2)

the most efficient method here would be elimination.

add (1) and (2) term by term to eliminate y

x + 0 = 3

x = 3

substitute x = 3 into either of the 2 equations and solve for y

substituting into (1)

5(3) + 3y = 6

15 + 3y = 6 ( subtract 15 from both sides )

3y = - 9 ( divide both sides by 3 )

y = - 3

solution is (3, - 3 )

Answer 2

`(3,-3)`

Explanation:

`5x + 3y = 6`

The most efficient method for this equation is elimination.

`x + 0 = 3`

`5(3) + 3y = 6`

Substitute x = 3 into any of the equation and solve for y.

`5(3) + 3y = 6`

`15 + 3y = 6`

`-15 -15`

`3y = - 9`

`(3y)/(3)=(-9)/(3)`

`y=-3`

`(3,-3)`