Algebra 1 Graphing Linear Equations Quiz: 10 Questions with Explanations

A \((0, -9)\)B \((0, 4)\)C \((9, 0)\)D \(\left(\frac{9}{4}, 0\right)\)

The constant b in y = mx + b is the y-intercept. The x-intercept is (9/4, 0).

A \(y = x + 2\)B \(y = \frac{1}{2}x + 1\)C \(y = 2x – 1\)D \(y = 2x + 1\)

The y-intercept is 1 and the line rises 2 for each 1 to the right, so the slope is 2.

A \((0, 3)\)B \((6, 0)\)C \((3, 0)\)D \((18, 0)\)

Let y = 0: 3x = 18, so x = 6. The point (0, 3) is the y-intercept.

A \(y = 2x + 8\)B \(y = -2x – 8\)C \(y = -2x + 8\)D \(y = \frac{1}{2}x + 8\)

Subtract 2x from both sides to get y = -2x + 8.

A \(y = 3\)B \(x = 3\)C \(y = 3x\)D \(x = -3\)

Every point on a vertical line has the same x-coordinate, here 3.

A \((3, -1)\)B \((3, 1)\)C \((-3, 1)\)D \((2, 3)\)

For x = 3, y = -6 + 5 = -1. The point (2, 3) would need y = 1.

A \(y = \frac{5}{2}x – 1\)B \(y = \frac{2}{5}x + 1\)C \(y = -\frac{2}{5}x – 1\)D \(y = \frac{2}{5}x – 1\)

The y-intercept is -1, and the line rises 2 for each 5 to the right, so the slope is 2/5.

A \(y – 1 = 3(x – 4)\)B \(y + 4 = 3(x + 1)\)C \(y – 4 = 3(x – 1)\)D \(y – 3 = 4(x – 1)\)

Point-slope form is y – y1 = m(x – x1). The y-coordinate 4 goes with y and the x-coordinate 1 goes with x.

A The tank is empty after 25 minutesB The tank starts with 25 gallonsC The tank loses 25 gallons per minuteD The tank is full after 25 minutes

At the x-intercept, y = 0 gallons. The y-intercept 50 is the starting amount and the slope -2 is the rate.

A 5B 8C 3D 10

The line is y = x + 3, so y = 5 + 3 = 8.