Topic Quiz A.1: Expressions and polynomials

Question 1 of 10 · Factor polynomials

No calculator

Which expression is a factor of x^2 + x - 30?

Answer choices
Hint

Factor the trinomial first: two numbers that multiply to -30 and add to +1.

Question 2 of 10 · Write linear expressions from context

A group of 20 people visits a zoo. Adult tickets cost $12 and child tickets cost $7. If a people in the group are adults and everyone else is a child, which expression gives the total cost of the tickets, in dollars?

Answer choices
Hint

If a of the 20 people are adults, how many are children? Write it with a.

Question 3 of 10 · Evaluate linear expressions

Drag and drop

Drag a value into each empty box to complete the table for the expression -2x + 5. Not every tile is used.

x-30.54
-2x + 5

Tap a tile, then tap a box to place it.

Hint

The coefficient is -2. For x = -3, think: negative times negative.

Question 4 of 10 · Evaluate polynomials

Priya evaluated x^2 - 3xy + y^2 when x = -1 and y = 4. Her work is shown.

StepWork
1(-1)^2 - 3(-1)(4) + (4)^2
2-1 + 12 + 16
327

Which statement correctly describes Priya's work?

Answer choices
Hint

Check each part of Step 2 separately: (-1)^2, then -3(-1)(4), then (4)^2.

Question 5 of 10 · Rational expression operations

Select all

Select all expressions that are equivalent to \dfrac{10 - 2x}{x^2 - x - 20} for all values of x where both are defined.

Select all that apply.

Answer choices
Hint

Factor -2 out of the numerator and factor the denominator. Remember that moving a negative sign between top and bottom does not change the value.

Question 6 of 10 · Evaluate rational expressions

Fill in

For what value of x does \dfrac{5x + 3}{x - 1} equal 6?

x =

Type your answer in the box. Fractions like 3/4 are fine.

Hint

Set the expression equal to 6 and multiply both sides by x - 1. Distribute the 6 to both terms.

Question 7 of 10 · Write rational expressions from context

No calculator

Which situation can be represented by the expression \dfrac{60}{x + 3}?

Answer choices
Hint

Translate each situation into an expression yourself. Watch where the 3 goes: inside the denominator, outside the fraction, or in the numerator.

Question 8 of 10 · Linear expressions: combine, factor, expand

Two students simplified 4 - 3(2x - 6) + 5x.

Dana: Step 1: 4 - 6x - 18 + 5x. Step 2: -x - 14.

Ben: Step 1: 1(2x - 6) + 5x. Step 2: 2x - 6 + 5x = 7x - 6.

Which statement is true?

Answer choices
Hint

Simplify it yourself first. What is (-3)(-6)? And may you subtract 4 - 3 before multiplying?

Question 9 of 10 · Polynomial operations

A polynomial q(x) satisfies (x - 2) \cdot q(x) = x^3 - 7x + 6 for every value of x. Which expression is q(x)?

Answer choices
Hint

q(x) = (x^3 - 7x + 6) \div (x - 2). Remember that x^3 - 7x + 6 has no x^2-term; write it as x^3 + 0x^2 - 7x + 6 before dividing.

Question 10 of 10 · Write polynomial expressions from context

Fill in

A rectangular metal plate measures (3x + 2) cm by (2x + 5) cm. Two square holes, each with sides of x cm, are cut out of the plate.

Write a simplified polynomial for the area of the remaining metal. Then find that area, in square centimeters, when x = 3.

cm²

Type your answer in the box. Fractions like 3/4 are fine.

Hint

Remaining area = plate area − 2 × (one hole's area). Simplify first, then substitute.

Formula sheet

Area

Area of a square s = length of a side
A = s^2
Area of a rectangle l = length, w = width
A = lw
Area of a parallelogram b = base, h = height (straight up from the base, not the slanted side)
A = bh
Area of a triangle b = base, h = height
A = \tfrac{1}{2}bh
Area of a trapezoid b_1 and b_2 = the two parallel sides, h = height
A = \tfrac{1}{2}h(b_1 + b_2)
Area of a circle r = radius (half of the diameter); \pi \approx 3.14
A = \pi r^2

Perimeter and circumference

Perimeter of a square s = length of a side
P = 4s
Perimeter of a rectangle l = length, w = width
P = 2l + 2w
Perimeter of a triangle s_1, s_2, s_3 = the three side lengths
P = s_1 + s_2 + s_3
Circumference of a circle the distance around a circle; r = radius, d = diameter, \pi \approx 3.14
C = 2\pi r = \pi d

Surface area (SA) and volume (V)

p = perimeter of the base with area B; \pi \approx 3.14

Rectangular prism l = length, w = width, h = height
SA = 2lw + 2lh + 2wh \qquad V = lwh
Right prism B = area of the base, p = perimeter of the base, h = height
SA = ph + 2B \qquad V = Bh
Cylinder r = radius of the base, h = height
SA = 2\pi rh + 2\pi r^2 \qquad V = \pi r^2 h
Pyramid B = area of the base, p = perimeter of the base, s = slant height, h = height
SA = \tfrac{1}{2}ps + B \qquad V = \tfrac{1}{3}Bh
Cone r = radius of the base, s = slant height, h = height
SA = \pi rs + \pi r^2 \qquad V = \tfrac{1}{3}\pi r^2 h
Sphere r = radius
SA = 4\pi r^2 \qquad V = \tfrac{4}{3}\pi r^3

Data

Mean (average) add all the values of the data set, then divide by how many values there are
\text{mean} = \dfrac{\text{total of the values}}{\text{number of values}}
Median
the middle value when the data are in order; with an even number of values, it is the mean of the two middle values

Algebra

Slope of a line (x_1, y_1) and (x_2, y_2) = two points on the line
m = \dfrac{y_2 - y_1}{x_2 - x_1}
Slope-intercept form of a line m = slope, b = y-intercept (where the line crosses the y-axis)
y = mx + b
Point-slope form of a line m = slope, (x_1, y_1) = a point on the line
y - y_1 = m(x - x_1)
Standard form of a quadratic equation a, b, c are numbers and a \ne 0
y = ax^2 + bx + c
Quadratic formula solves ax^2 + bx + c = 0
x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}
Pythagorean theorem in a right triangle: a, b = the two legs, c = the hypotenuse (the longest side, across from the right angle)
a^2 + b^2 = c^2
Simple interest I = interest, P = principal (the amount saved or borrowed), r = rate per year as a decimal, t = time in years
I = Prt
Distance = rate × time d = distance, r = rate (speed), t = time
d = rt
Total cost
\text{total cost} = (\text{number of units}) \times (\text{price per unit})