Solving Equatiosn withParentheses

Takitia

New member
Joined
Jul 11, 2007
Messages
18
Not sure on what to do next.

7(3x+4)=8(2x+5)+13
21x+28 =16x40+13 after this point I am confused and stuck. I know I am
to combine like terms, but not sure which one to do first.
 

jonboy

Full Member
Joined
Jun 8, 2006
Messages
547
Hello, Takita!

Great awareness so far of the Distributive Property so far!

\(\displaystyle \L \;21x\,+\,28\,=\,16x\,+\,40\,+\,13\)

First since you have normal, like natural numbers on the right side of the equation, combine them:

\(\displaystyle \L \;21x\,+\,28\,=\,16x\,+\,53\)

Now you can either subtract the 21x or the 16x from both sides of the equation; But the subtraction of 16x causes no negatives for the coefficient x so let's do that:

\(\displaystyle \L \;5x\,+\,28\,=\,53\)

...Now just subtract 28 from both sides:\(\displaystyle \L \;5x\,=\,25\;\;\Rightarrow\;\;x\,=\,5\)
 
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