Question

practice: subtract like terms. show the step in which you change the subtraction to addition. then give the final answer.
1.) $-4x - (7x) = -4x + (-7x) = \underline{\quad\quad\quad}$ 2.) $15x - 18x = 15x + (-18x) = \underline{\quad\quad\quad}$
3.) $2x - 2x =$ 4.) $3x - (-2x) = 3x + (+2x) = \underline{\quad\quad\quad}$
5.) $-8x - (-2x) =$ 6.) $-6x - 2x =$
7.) $-5x - (-2x) =$ 8.) $9x - 12x =$
9.) $-8x - 8x =$ 10.) $6x - (-4x) =$

selected answers to subtraction problems above: 2.) $-3x$ 5.) $-6x$ 7.) $-3x$ 10.) $10x$

mixed practice: adding and subtracting like variable terms
1.) $-3x + 5x =$ 8.) $20b + (-30b) =$
2.) $-3x - 5x =$ 9.) $20b - (-30b) =$
3.) $6y + (-8y) =$ 10.) $-7xy + (-3xy) =$
4.) $6y - (-8y) =$ 11.) $-7xy - (-3xy) =$
5.) $17a + -3a =$ 12.) $4w + 8w =$
6.) $17a - (-3a) =$ 13.) $4w - 8w =$
7.) $3y - 7y =$ 14.) $-3y - (-7y) =$

Explanation:

Step1: Solve \(-4x - (7x)\)

First, change subtraction to addition: \(-4x + (-7x)\). Then combine like terms: \((-4 - 7)x = -11x\).

Step2: Solve \(15x - 18x\)

Change subtraction to addition: \(15x + (-18x)\). Combine like terms: \((15 - 18)x = -3x\).

Step3: Solve \(2x - 2x\)

Change subtraction to addition: \(2x + (-2x)\). Combine like terms: \((2 - 2)x = 0\).

Step4: Solve \(3x - (-2x)\)

Change subtraction to addition: \(3x + (+2x)\). Combine like terms: \((3 + 2)x = 5x\).

Step5: Solve \(-8x - (-2x)\)

Change subtraction to addition: \(-8x + (+2x)\). Combine like terms: \((-8 + 2)x = -6x\).

Step6: Solve \(-6x - 2x\)

Change subtraction to addition: \(-6x + (-2x)\). Combine like terms: \((-6 - 2)x = -8x\).

Step7: Solve \(-5x - (-2x)\)

Change subtraction to addition: \(-5x + (+2x)\). Combine like terms: \((-5 + 2)x = -3x\).

Step8: Solve \(9x - 12x\)

Change subtraction to addition: \(9x + (-12x)\). Combine like terms: \((9 - 12)x = -3x\).

Step9: Solve \(-8x - 8x\)

Change subtraction to addition: \(-8x + (-8x)\). Combine like terms: \((-8 - 8)x = -16x\).

Step10: Solve \(6x - (-4x)\)

Change subtraction to addition: \(6x + (+4x)\). Combine like terms: \((6 + 4)x = 10x\).

Step11: Solve \(-3x + 5x\)

Combine like terms: \((-3 + 5)x = 2x\).

Step12: Solve \(-3x - 5x\)

Change subtraction to addition: \(-3x + (-5x)\). Combine like terms: \((-3 - 5)x = -8x\).

Step13: Solve \(6y + (-8y)\)

Combine like terms: \((6 - 8)y = -2y\).

Step14: Solve \(6y - (-8y)\)

Change subtraction to addition: \(6y + (+8y)\). Combine like terms: \((6 + 8)y = 14y\).

Step15: Solve \(17a + (-3a)\)

Combine like terms: \((17 - 3)a = 14a\).

Step16: Solve \(17a - (-3a)\)

Change subtraction to addition: \(17a + (+3a)\). Combine like terms: \((17 + 3)a = 20a\).

Step17: Solve \(3y - 7y\)

Combine like terms: \((3 - 7)y = -4y\).

Step18: Solve \(20b + (-30b)\)

Combine like terms: \((20 - 30)b = -10b\).

Step19: Solve \(20b - (-30b)\)

Change subtraction to addition: \(20b + (+30b)\). Combine like terms: \((20 + 30)b = 50b\).

Step20: Solve \(-7xy + (-3xy)\)

Combine like terms: \((-7 - 3)xy = -10xy\).

Step21: Solve \(-7xy - (-3xy)\)

Change subtraction to addition: \(-7xy + (+3xy)\). Combine like terms: \((-7 + 3)xy = -4xy\).

Step22: Solve \(4w + 8w\)

Combine like terms: \((4 + 8)w = 12w\).

Step23: Solve \(4w - 8w\)

Change subtraction to addition: \(4w + (-8w)\). Combine like terms: \((4 - 8)w = -4w\).

Step24: Solve \(-3y - (-7y)\)

Change subtraction to addition: \(-3y + (+7y)\). Combine like terms: \((-3 + 7)y = 4y\).

Answer:

1. \(-11x\)
2. \(-3x\)
3. \(0\)
4. \(5x\)
5. \(-6x\)
6. \(-8x\)
7. \(-3x\)
8. \(-3x\)
9. \(-16x\)
10. \(10x\)
11. \(2x\)
12. \(-8x\)
13. \(-2y\)
14. \(14y\)
15. \(14a\)
16. \(20a\)
17. \(-4y\)
18. \(-10b\)
19. \(50b\)
20. \(-10xy\)
21. \(-4xy\)
22. \(12w\)
23. \(-4w\)
24. \(4y\)