# Given f(x) = 12x + 6 - 18x, find x if f(x) = -60

#### student0928

##### New member
I'm old school and didn't learn algebra the way kids do it now. Can anyone help me with this?

Given f(x)=12x+6-18x

Find x if f(x)=-60

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#### tkhunny

##### Moderator
Staff member
I'm old school and didn't learn algebra the way kids do it now. Can anyone help me with this?

Given f(x)=12x+6-18x

Find x if f(x)=-60

For starters, we probably need a better description for f(x).

Anyway, if we want f(x) = 60, simply do the substitution.

60 = {full expression for f(x)}

#### Dr.Peterson

##### Elite Member
I'm old school and didn't learn algebra the way kids do it now. Can anyone help me with this?

Given f(x)=12x+6-18x

Find x if f(x)=-60

Essentially, you are told that "f(x)" is a name for 12x+6-18x. (I'm assuming that this is copied correctly; it feels wrong because it can be simplified, but that is not really a problem.) So you are being told to solve the equation

12x+6-18x = -60

The rest should be what you learned in algebra! If you didn't learn function notation, you can read the section in her book introducing it, and you'll find that it's really nothing more than a notation for things you've seen before.

#### Jomo

##### Elite Member
I'm old school and didn't learn algebra the way kids do it now. Can anyone help me with this?

Given f(x)=12x+6-18x

Find x if f(x)=-60