How do you evaluate #-14c - - 12c + 1= - 7#?

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Answer 1 · 2018-03-28T21:37:18

#c=4#

Since we are subtracting a negative #12c# this turns into adding #12c#. Thus, we have

#-14c+12c+1=-7#

We can simplify the terms on the left to get

#-2c+1=-7#

Next, we can subtract #1# from both sides to get:

#-2c=-8#

Next, we can divide both sides by #-2# to get

#c=4#

Hope this helps!

Answer 2 · 2018-03-28T21:43:31

If you treat subtraction of a negative value as addition of a positive, you can simplify the expression and solve: #c=4#

The first thing to do is to combine like terms. both the 14 and 12 are multiplied by #-c#, so we can combine those:

#color(blue)(-14c)-color(green)(-12c)+1=-7#

#rArr -(color(blue)(14)-color(green)(12))c+1=-7#

#rArr -2c+1=-7#

Now, let's move the +1 constant to the Right Hand Side. This will be achieved by subtracting 1 from both sides:

#-2c cancel(+1-1)=-7-1#

#rArr -2c=-8#

Finally, we divide both sides by any constants that our unknown variable is multiplied by. In this case, that constant is -2:

#(cancel(-2)c)/cancel(-2)=(-8)/(-2)#

#color(red)(rArr c=4)#