Question

Which ordered pair is the best estimate of the solution of the system of equations?

(i will report you if you answer something incorrect)

(6.8, 2.1)

(6.1, 2.1)

(6.1, 2.9)

(6.8, 2.9)

Answer 1

• A. (6.8, 2.1)

Explanation:

System as per the graphed lines:

• y = 1/6x + 1
• 3x - 2y = 16

The are two solutions.

Solution 1

• Take the coordinates of the intersection point and compare with the answer choices.
• This is the point with x-coordinate close to 7 and y-coordinate close to 2. The best choice is A.

Solution 2

Solve by substitution.

Substitute y into second equation:

• 3x - 2(1/6x + 1) = 16
• 3x - 1/3x - 2 = 16
• 8/3x = 18
• x = 18*3/8
• x = 6.75

Find y:

• y = 1/6x + 1
• y = 1/6(6.75) + 1
• y = 2.125

The best estimate is x = 6.8 and y = 2.1

Correct choice is A