Grade 8 Math Test Flashcards

What is the solution to the equation 3(x - 4) = 2x + 1?

Answer: x = 13

Distribute: 3x - 12 = 2x + 1. Subtract 2x from both sides: x - 12 = 1. Add 12: x = 13.

A line passes through the points (2, 5) and (6, 13). What is the slope of this line?

Answer: 2

Slope = (y₂ - y₁)/(x₂ - x₁) = (13 - 5)/(6 - 2) = 8/4 = 2.

Which of the following is equivalent to 5⁻³?

Answer: 1/125

A negative exponent means take the reciprocal: 5⁻³ = 1/5³ = 1/125.

The volume of a cylinder is given by V = πr²h. If r = 3 cm and h = 7 cm, what is the approximate volume? (Use π ≈ 3.14)

Answer: 197.8 cm³

V = π(3²)(7) = π(9)(7) = 63π ≈ 63 × 3.14 ≈ 197.82 cm³.

A scatter plot shows the number of hours students study and their test scores. As study hours increase, test scores also increase. What type of correlation does this represent?

Answer: Positive correlation

When both variables increase together, this is a positive correlation — the data points trend upward from left to right.

The equation y = 2x - 3 represents a linear function. What is the y-intercept of this line?

Answer: −3

In slope-intercept form y = mx + b, the y-intercept is b. In y = 2x - 3, b = -3.