Algebra 1

End-of-Unit Assessment

End-of-Unit Assessment
1.

Select all equations that are equivalent to (5x+6)2=3(4x+12)\frac{(5x+6)}2=3-(4x+12).

Answer: B, C, E

2.

A phone company charges a base fee of $12 per month plus an additional charge per minute. The monthly phone cost CC can be represented by this equation: C=12+amC=12+a \boldcdot m, where aa is the additional charge per minute, and mm is the number of minutes used.

Which equation can be used to find the number of minutes a customer used if we know aa and CC?

A.

m=(C12)am=\frac{(C-12)}{a}

B.

m=(C12)am = (C-12) - a

C.

m=C12am = C - 12a

D.

m=Ca12m = \frac {C}{a} - 12

Answer: A

3.

Tickets to the zoo cost $12 for adults and $8 for children. The school has a budget of $240 for the field trip. An equation representing the budget for the trip is 240=12x+8y240=12x+8y. Here is a graph of this equation.

Graph of a line.
Graph of a line. Horizontal axis from 0 to 32, by 2's, number of adults. Vertical axis from 0 to 32, by 2's, number of children. Line begins on the y axis at 30, goes through 4 comma 24, 12 comma 12, and ends on the x axis at 20.

Select all the true statements.

Answer: A, C, E

4.

A pizza shop sells pizzas that are 10 inches (in diameter) or larger. A 10-inch cheese pizza costs $8. Each additional inch costs $1.50, and each additional topping costs $0.75.

Write an equation that represents the cost of a pizza. Be sure to specify what the variables represent.

Answer:

Sample response: CC=cost of pizza, ss=additional inches above 10 for the pizza diameter, tt=number of toppings. C=8+1.50s+0.75tC=8+1.50s+0.75t.

5.

Consider this system of equations: {y=-12x+56x7y=22\displaystyle \begin {cases} y = \text{-}\frac{1}{2}x + 5 \\ 6x - 7y = 22 \end{cases} Solve the system by graphing. Label each graph and the solution.

A blank coordinate grid with origin 0. X axis, negative 8 to 11, by 1's. Y axis from negative 6 to 5, by 1's.

Answer:

(6,2)(6, 2) or x=6,y=2x=6, \, y=2

6.

Solve the system of equations without graphing. Show your reasoning. {2y=x44x+3y=5\displaystyle \begin{cases} 2y=x-4 \\ 4x+3y=5 \end{cases}

Answer:

(2,1)(2, -1) or x=2,y=1x=2, \, y=-1

7.

The system of equations {4x+6y=242x+y=8\begin{cases} 4x+6y=24\\ 2x+y=8 \end{cases} has exactly one (x,y)(x,y) pair for its solution.

  1. If we double each side of the second equation, 2x+y=82x+y=8, we have 4x+2y=164x+2y=16. Explain why the same (x,y)(x,y) pair that is the solution to the system is also a solution to this new equation.

  2. If we add the two equations in the original system, we have 6x+7y=326x +7y=32. Explain why the same (x,y)(x,y) pair is also a solution to this equation.

Answer:

  1. Multiplying both sides of an equation by 2 means that the amount on each side is twice as large, but the two sides are still equal. Since the original equation had the solution pair, the new one will too.
  2. Since 4x+6y=244x+6y=24, adding this equation to 2x+y=82x+y=8 is like adding 24 to each side. Adding the same thing to both sides doesn't change the solutions.