Question

How can you model and solve a multi step equation (HELP I NEED THE ANSWER BY TONIGHT)

Answer 1

Short answer:

The main goal in solving multi-step equations, just like in one-step and two-step equations, is to isolate the unknown variable on one side of the equation while keeping the constant or number on the opposite side.

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Longer answer:

You can solve a two-step equation by getting the variable alone on one side of the equation. To do that, you'll need to use inverse operations.

For an example, lets try 3x + 8 = 20

3x + 8 = 20

3x + 8 – 8 = 20 – 8 Subtract 8 from both sides.

3x = 12

$\frac{3x}{3} =\frac{12}{3}$                             Divide both sides by 3.

x = 4

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Some equations have variables on both sides of the equal sign. To solve these types of equations, use inverse operations to get the variables all on one side of the equal sign. Then, use inverse operations to solve for the variable.

For an example, solve 2b + 8 = 7b – 2. First, get the terms with variables on the same side of the equation. Then, solve for b

2b + 8 = 7b – 2

2b + 8 – 2b = 7b – 2 – 2b Subtract 2b from both sides.

8 = 5b – 2

8 + 2 = 5b – 2 + 2     Add 2 to both sides.

10 = 5b

$\frac{10}{5} = \frac{5b}{5}$        Divide both sides by 5.

2 = b

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Sometimes, equations use parentheses to show multiplication. You can use the distributive property to help solve these types of equations.

For example, solve 2(r+3)=5r–12. First, distribute the 2 to both terms inside the parentheses. Then, get the variables all on one side of the equal sign. Last, solve for r.

2(r + 3) = 5r – 12

2(r) + 2(3) = 5r – 12       Apply the distributive property.

2r + 6 = 5r – 12

2r + 6 – 2r = 5r – 12 – 2r Subtract 2r from both sides.

6 = 3r – 12

6+12 = 3r – 12 + 12       Add 12 to both sides.

18 = 3r

$\frac{18}{3} =\frac{3r}{3}$         Divide both sides by 3.

6 = r

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