Subject: 2-step equations

Name: Jen
Who is asking: Student
Level: Middle

i don't get how you find the answer to these equations:

140= -4 -12e

x/-2 + 6 = 4

Hi Jen,

A useful way to think of an equation is as a balance. As with a balance, if you add the same amount to each side the balance is maintained.

For your first problem

140 = -4 -12e

the object is to end with an equation of the form

e = some number

To start, add 12e to each side to get

140 + 12e = -4 -12e +12e
which simplifies to
140 + 12e = -4
Now add -140 to both sides
-140 + 140 + 12e = -140 -4
which becomes
12e = -144

Again, seeing the equation as a balance, divide both sides by 12 to get

12e/12 = -144/12
e = -12
If you want to see another example you can look at a problem sent to us by Shelley's Mom

Now try your second problem.

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