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Last updated: October 22, 2026 · Written by the Math Made Easy math teachers
Standards: F-IF.C.7a, F-LE.A.1a, F-LE.A.2, A-CED.A.2 · Level: Grade 9 Algebra 1
Question 1 Slope (2 points)
Slope = (−1 − 7) ÷ (5 − (−3)) = −8 ÷ 8 = −1.
−1
Scoring: 1 point for the correct setup, 1 point for the answer.
Question 2 Line through two points (2 points)
Slope = (9 − 3) ÷ (8 − 4) = 6 ÷ 4 = 3/2.
y − 3 = (3/2)(x − 4), so y = 1.5x − 6 + 3 = 1.5x − 3.
Check: 1.5(8) − 3 = 9.
y = 1.5x − 3
Scoring: 1 point for the slope, 1 point for the equation.
Question 3 Rewrite in slope-intercept form (2 points)
−2y = −5x + 14, so y = (5/2)x − 7.
y = 2.5x − 7; slope 2.5; y-intercept −7
Scoring: 1 point for the equation, 1 point for the slope and intercept.
Question 4 Equation from a graph (2 points)
Slope = (−1 − 3) ÷ (2 − (−2)) = −4 ÷ 4 = −1.
Point-slope: y − 3 = −(x + 2), so y = −x + 1.
Slope −1; y = −x + 1
Scoring: 1 point for the slope, 1 point for the equation.
Question 5 Parallel line (2 points)
The slope is −3. y − 6 = −3(x + 2), so y = −3x − 6 + 6 = −3x.
Check: −3(−2) = 6.
y = −3x
Scoring: 1 point for the slope, 1 point for the equation.
Question 6 Perpendicular line (2 points)
The negative reciprocal of 2/5 is −5/2.
y + 3 = −(5/2)(x − 10), so y = −2.5x + 25 − 3 = −2.5x + 22.
Check: −2.5(10) + 22 = −3.
y = −2.5x + 22
Scoring: 1 point for the slope, 1 point for the equation.
Question 7 Kayak rental model (3 points)
(a) (75 − 39) ÷ (5 − 2) = 36 ÷ 3 = 12 dollars per hour.
(b) C − 39 = 12(h − 2), so C = 12h + 15.
(c) The intercept 15 is the flat fee in dollars, the cost for 0 hours.
C = 12h + 15
Scoring: 1 point per part.
Question 8 Booth sales (3 points)
(a) 3s + 5l = 60. When l = 0, s = 20; when s = 0, l = 12. Intercepts (20, 0) and (0, 12).
(b) (0, 12): if no small bags are sold, 12 large bags are needed to reach $60.
(c) 3s + 5(6) = 60, so 3s = 30 and s = 10.
3s + 5l = 60; 10 small bags
Scoring: 1 point per part.
Question 9 Compare two lines (2 points)
(a) Slope of B = (12 − 3) ÷ (4 − 1) = 3.
(b) A has slope −2, so it is decreasing; B has slope 3, so it is increasing and steeper because |3| > |−2|.
B is increasing and steeper
Scoring: 1 point per part.