solving 2-step equations ax + b = c. keep it balanced just like when solving a one- step equation...
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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