Write y = mx + b from a slope and a point, a y-intercept and a point, or two points

Answer Key - Grade 8 Math Worksheet

Circle the best answer, or write your answer on the line.

1. 1.

   Kira's line has slope 3 and passes through (-1, -2). What rule, written as y = mx + b, gives the line?

   y = 3x + 1
2. 2.

   Luz's line has slope 1/2 and passes through (4, 5). What rule, written as y = mx + b, gives the line?

   y = x ÷ 2 + 3
3. 3.

   Milo's line has slope -3 and passes through (2, -4). What rule, written as y = mx + b, gives the line?

   y = -3x + 2
4. 4.

   Noah's line has slope 5 and passes through (2, 3). What rule, written as y = mx + b, gives the line?

   y = 5x − 7
5. 5.

   Pia's line has y-intercept -3 and passes through (2, 5). What rule, written as y = mx + b, gives the line?

   y = 4x − 3
6. 6.

   Ren's line has y-intercept 8 and passes through (2, 2). What rule, written as y = mx + b, gives the line?

   y = -3x + 8
7. 7.

   Tala's line has y-intercept 1 and passes through (4, 9). What rule, written as y = mx + b, gives the line?

   y = 2x + 1
8. 8.

   Zee's line has y-intercept -5 and passes through (2, -1). What rule, written as y = mx + b, gives the line?

   y = 2x − 5
9. 9.

   Esme's line passes through (1, -1) and (4, 8). What rule, written as y = mx + b, gives the line?

   y = 3x − 4
10. 10.

    Jun's line passes through (3, 4) and (6, 6). What rule, written as y = mx + b, gives the line?

    y = 2x ÷ 3 + 2