Change between Ax + By = C and y = mx + b, and read the slope and intercepts

Answer Key - Grade 9 Math Worksheet

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

1. 1.

   The line is 3x + 2y = 12. In math club, Ren meets 3x + 2y = 12. What rule in y = mx + b form gives the same line?

   y = -3x/2 + 6
2. 2.

   The line is 5x + 2y = 10. In a puzzle book, Zee meets 5x + 2y = 10. What rule in y = mx + b form gives the same line?

   y = -5x/2 + 5
3. 3.

   The line is 6x + 4y = 20. On a poster, Bo meets 6x + 4y = 20. What rule in y = mx + b form gives the same line?

   y = -3x/2 + 5
4. 4.

   Multiply by 3 to clear the fraction. In math club, Pia's rule is y = 2x/3 + 4. What is the same line in the form Ax + By = C, with whole numbers and A positive?

   2x − 3y = -12
5. 5.

   Multiply by 4 to clear the fraction. On a worksheet, Jun's rule is y = 3x/4 − 2. What is the same line in the form Ax + By = C, with whole numbers and A positive?

   3x − 4y = 8
6. 6.

   Multiply by 3 to clear the fraction. In the warm-up, Luz's rule is y = x/3 − 5. What is the same line in the form Ax + By = C, with whole numbers and A positive?

   x − 3y = 15

7. Read this first

   Input–output table

   x	y
   0	5
   4	-1

   Solve for y to read the slope.

8. 7.

   Ari sees the line 6x + 4y = 20 in math club. What is its slope?

   -3/2
9. 8.

   Noah sees the line 4x + 6y = 18 in math club. What is its slope?

   -2/3
10. 9.

    Esme sees the line 10x + 4y = 12 in math club. What is its slope?

    -5/2
11. 10.

    Ren sees the line 4x − 5y = 15 in math club. What is its slope?

    4/5