Last updated: October 22, 2026 · Written by the Math Made Easy math teachers

The last six problems turn real limits into constraints and test feasible points (A-CED.A.3): budgets, shipping, food plans and earnings.
Standards: A-REI.D.12, A-CED.A.3 · Level: Grade 9 Algebra 1
Problem 1 Test two points ★★★
Decide whether each point is a solution of y ≥ 2x + 1: (3, 9) and (1, 2).
Problem 2 Solid or dashed ★★★
Tell whether the boundary line is solid or dashed. (a) y < 7x − 9 (b) y ≥ −5x + 11 (c) x ≤ 13.
Problem 3 Which side to shade ★★★
For y > −6x + 14, test the origin and say which side of the boundary to shade.
Problem 4 Write from a graph ★★★
Write the inequality graphed below.
Problem 5 Check a point in a system ★★★
Is (−2, 3) a solution of the system y < x + 6 and y ≥ −x?
Problem 6 Graph a solid half-plane ★★★
Graph y ≤ −12x + 3.
Problem 7 Graph from standard form ★★★
Graph 3x + 2y > 12.
Problem 8 Vertical and horizontal boundaries ★★★
Graph the system x < −1 and y ≥ 2.
Problem 9 Solve for y first ★★★
Rewrite 4x − 2y ≤ 10 so that y is alone, then describe the graph.
Problem 10 Write a system from a graph ★★★
Write the system of inequalities whose solution is the shaded region.
Problem 11 Graph a system ★★★
Graph the system y ≥ x − 2 and y < −x + 4, and say whether (0, 0) is a solution.
Problem 12 Test several points ★★★
Which of (4, 1), (5, 3), (3, −2) and (6, 0) satisfy both 2x + y ≤ 10 and x − y > 1?
Problem 13 Triangle region ★★★
Graph the system x ≥ 0, y ≥ 0 and x + y ≤ 9, and list the corner points.
Problem 14 No overlap ★★★
Explain why y ≥ 8x + 3 and y ≤ 8x − 7 has no solution.
Problem 15 Snack cart budget ★★★
A cart sells pretzels at $2.50 and juices at $2.00. A club spends at most $30. Write an inequality, then test (6, 7), (8, 5) and (9, 6), where the first number is the pretzels. Use the graph.
Problem 16 Bake sale constraints ★★★
A bake sale will have at most 40 items, with at least 12 cupcakes. Let c be cupcakes and b brownies. Write the constraints, find the corner points of the feasible region and decide whether (15, 20) and (10, 25) are feasible.
Problem 17 Shipping limits ★★★
A shipment of robotics kits (3 pounds each) and sensors (0.5 pound each) can weigh at most 30 pounds, and it needs at least 2 kits. Write the constraints. Is (5, 20) allowed? Is (9, 10)? How many sensors fit with 2 kits?
Problem 18 Hiking food plan ★★★
A hiker needs at least 2,000 calories from energy bars (250 calories, 2 oz) and trail packs (400 calories, 5 oz) and can carry at most 40 oz of food. Write a system. Test (4, 3), (2, 2) and (10, 4), where the first number is the bars.
Problem 19 Weekly earnings plan ★★★
Ava earns $12 per hour babysitting and $15 per hour tutoring. She wants to earn at least $240 a week and work at most 20 hours. Write a system, and decide which of (10, 8), (15, 3), (4, 12) and (5, 15) are feasible (babysitting hours first).
Problem 20 Shirts and hats ★★★
A club sells shirts at $15 and hats at $9. It wants revenue of at least $360 but can stock at most 30 items in total. Write the system, find where the two boundary lines meet and decide whether 20 shirts and 8 hats work.

