Question

Which ordered pair is the best estimate for the solution to the system?

(4.8,5.2)

(5.5,4.3)

(5.1,4.8)

(6.5,5.2)

Answer 1

(5.5, 4.3 )

Explanation:

Given the 2 equations

4x - 15y = - 43 → (1)

2x - 3y = - 2 → (2)

Multiplying (2) by - 2 and adding to (1) eliminates the term in x

- 4x + 6y = 4 → (3)

Add (1) and (3) term by term to eliminate x, that is

- 9y = - 39 ( divide both sides by - 9 )

y =
`(39)/(9)` ≈ 4.3 ( to 1 dec. place )

Substitute this value into either of the 2 equations and solve for x

Substituting into (2)

2x - 3(
`(39)/(9)` ) = - 2

2x - 13 = - 2 ( add 13 to both sides )

2x = 11 ( divide both sides by 2 )

x = 5.5

Best solution is (5.5, 4.3 )

Answer 2

5.5, 4.333 or 13/3

Explanation:

Use substitution method.