Week 5 Quiz

Which ordered pair is a solution of the system y = 3x + 4 and y = −2x + 14?

Select one.

• (1, 7)
• (2, 10)
• (0, 4)
• (10, 2)

A trail mix has twice as many cups of oats y as cups of nuts x, and 9 cups in all: y = 2x and x + y = 9. Solve by substitution.

Select one.

• (3, 6)
• (6, 3)
• (9, 18)
• (4.5, 9)

A team played 10 games and won 4 more than it lost, so x + y = 10 and x − y = 4, with wins x and losses y. Solve by elimination.

Select one.

• (14, −4)
• (3, 7)
• (7, 3)
• (6, 4)

To eliminate y from 2x + 3y = 12 and x − y = 1, you multiply every term of x − y = 1 by 3. Which equation results?

Select one.

• 3x − 3y = 1
• 3x − 3y = 3
• 3x − y = 3
• x − 3y = 3

Solve the snack-budget system 2x + 3y = 12 and x − y = 1, where x is snacks and y is drinks.

Select one.

• (2, 3)
• (6, 0)
• (4, 3)
• (3, 2)

Solving x + y = 3 and x + y = 7 by subtracting the equations leaves 0 = 4. What does that tell you about the system?

Select one.

• It has no solution: the system is inconsistent and its lines are parallel.
• It has infinitely many solutions: the system is dependent and its lines coincide.
• It has exactly one solution, at x = 0.
• It has exactly one solution, the pair (0, 4).

Consider the system 2x + y = 5 and 4x + 2y = 10. Select every true statement.

Select every option that applies.

• Doubling the first equation and subtracting leaves 0 = 0.
• The pair (1, 3) is a solution of the system.
• The system has no solution.
• The two lines are parallel and never meet.
• Both equations describe the same line, y = −2x + 5.

A club's T-shirt order costs C = 60 + 5x dollars for x shirts, and the shirts bring in R = 15x dollars. Setting 15x = 60 + 5x, how many shirts must the club sell to break even?

Select one.

• 4
• 3
• 6
• 12

Where y = 3x + 4 meets y = −2x + 14, the two expressions are equal: 3x + 4 = −2x + 14. Solve for x.

Select one.

• x = 10
• x = 3.6
• x = −2
• x = 2

True or false: the point (2, 2) is a solution of the system y > x and y < 4.

True or false.

• True
• False