Solving Equations Using Addition and Subtraction

What is the first step to solve this equation? 5x + 6 = 10 + 3x + 4x

• Add 4x to both sides of the equation

• Combine the terms 3x and 4x on the same side of the equation

• Add 5x and 6 to get 11x

• Combine the terms 5x and 3x and 4x to get 12x

What is the first step to solve this equation?

2x + 3(5x - 7) = 47

• Add 7 to both sides

• Combine 2x and 5x

• Distribute the 3 to 5x and - 7

• Subtract 2x from 5x

Find the error in the problem.

• Should have added 19 to -1.

• Should have subtracted 3k instead of adding 3k to both sides.

• Should have gotten k = 20 since two negatives make a positve.

• There is no error.

What is the first step to solve this equation? (3n - 4) + (-2 + 2n) = 9 

• Combine 3n and -4 and also combine -2 and 2n

• Add 3n to both sides of the equation

• Subtract 2n from both sides of the equation

• Combine 3n and 2n and also combine -4 and -2

What is the next step to solve this equation?
3x + 6 = 10 + 7x

• Add 6 to both sides of the equation

• Add 10 to both sides of the equation

• Add 7x to both sides of the equation

• Subtract 7x from both sides of the equation

Which would NOT be an acceptable next step in solving this equation? −4x − 7 = 3x + 2

• Subtract 2 from both sides

• Combine -4x and 3x to make -1x

• Subtract 3x from both sides

• Add 4x to both sides

What should be the first two steps to solve this equation? 2x +4(3x + 6) = 90

• combine 2x and 3x and then distribute the 4.

• subtract 6 from both sides and then divide by 4

• distribute the 4 and then combine like terms by addition

• combine 2x and 3x and then subtract 6 from both sides

What operation did he perform to get from Step 1 to Step 2?

• Subtracted 2x from both sides of the equation

• Subtracted 9 from both sides of the equation

• Multiplied both sides of the equation by 3

• Added -3 to both sides of the equation

Solve:

7x + 19 = -2x + 55

• 4

• 14.8

• 8.2

• -4

Solve:

2(2x + 3) = -6(x + 9)

• 2

• 6

• -6

• 7.5