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

Answer Key - Grade 9 Math Worksheet - Building Confidence

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

1. 1.

   The line is 2x + y = 9. Ren rewrites 2x + y = 9 by taking 2x from both sides: y = 9 − 2x. What is the rule in y = mx + b form?

   y = -2x + 9
2. 2.

   The line is 3x + y = 5. Kira rewrites 3x + y = 5 by taking 3x from both sides: y = 5 − 3x. What is the rule in y = mx + b form?

   y = -3x + 5
3. 3.

   The line is 4x + y = 9. Zee rewrites 4x + y = 9 by taking 4x from both sides: y = 9 − 4x. What is the rule in y = mx + b form?

   y = -4x + 9
4. 4.

   The line is x + y = 6. Milo rewrites x + y = 6 by taking x from both sides: y = 6 − x. What is the rule in y = mx + b form?

   y = -x + 6

5. Read this first

   Input–output table

   x	y
   0	9
   1	7
   2	5
   3	3

6. 5.

   Pia rewrote 2x + y = 9 as y = 9 − 2x. What is the slope of the line?

   -2
7. 6.

   Jun rewrote 5x + y = 4 as y = 4 − 5x. What is the slope of the line?

   -5
8. 7.

   Tala rewrote 4x + y = 10 as y = 10 − 4x. What is the slope of the line?

   -4
9. 8.

   The line is x + 4y = 20. Luz's line is x + 4y = 20. At x = 0 the row says 4y = 20. What is the y-intercept?

   5
10. 9.

    The line is 3x + 5y = 20. Ari's line is 3x + 5y = 20. At x = 0 the row says 5y = 20. What is the y-intercept?

    4
11. 10.

    The line is x + 3y = 18. Esme's line is x + 3y = 18. At x = 0 the row says 3y = 18. What is the y-intercept?

    6