Solving 2-step equationsSolving 2-step equations

ax + b = cax + b = c

Keep it balancedKeep it balanced

•Just like when solving a Just like when solving a one-step equation keep it one-step equation keep it balanced.balanced.

•Save the co-efficient until Save the co-efficient until last.last.

So what do we do first?So what do we do first?

•In the equation In the equation

•2x + 4 = 122x + 4 = 12 Our first step will be to Our first step will be to subtract the 4 from each subtract the 4 from each side of the equation.side of the equation.

Step 1:Step 1:

2x + 4 = 122x + 4 = 12

-4 = -4 -4 = -4

2x = 82x = 8

Now we have a one-Now we have a one-step equation.step equation.

Step 2:Step 2:

Divide by both sides by 2Divide by both sides by 2

2x2x = = 8 8

2 22 2

x = 4x = 4

Now you try oneNow you try one

2x + 5 = 152x + 5 = 15

Which operation should you Which operation should you do first? do first?

Subtract the 5 firstSubtract the 5 first

2x + 5 = 152x + 5 = 15

What should your second What should your second step be?step be?

Divide by 2Divide by 2

So what was your answer?So what was your answer?

2x + 5 = 152x + 5 = 15

- 5 = -5 - 5 = -5

2x2x = = 10 10

2 22 2

x = 5x = 5

What if there is division in What if there is division in the equation?the equation?

XX - 6 = 25 - 6 = 25

44

What is your first step?What is your first step?

Add the 6 to each sideAdd the 6 to each side

What is your second step?What is your second step?

XX - 6 = 25 - 6 = 25

44

Multiply by 4Multiply by 4

So what is your answer?So what is your answer?

XX - 6 = 25 - 6 = 25 44 + 6 = + 6 + 6 = + 6 xx = 31 = 31 44

Now multiply by 4Now multiply by 4

4* 4* XX = 31 * 4 = 31 * 4 44

x = 124x = 124