by tommywallach Fri Nov 15, 2013 6:27 pm
Hey Flavia,
Glad to help! Just so you know, we use the ^ symbol to do exponents (just so you don't have to type it out like that next time!).
a^2/2 + a/2 = 6
All we have to do is multiply everything by 2. Usually, when you're doing algebra, a good start is to get rid of denominators.
a^2 + a = 12
Now we can see this will be a quadratic (if you don't know what that is, time to hit the books!). Always set a quadratic equal to zero, in this case, by subtracting 12 from both sides.
a^2 + a - 12 = 0
In a quadratic, we solve by finding two numbers that multiply to the constant (-12, in this case) and sum to the coefficient on a (the invisible 1, in this case). This two numbers here would be -3 and 4, which we put in parentheses like so:
(a + 4) (a - 3) = 0
Our two solutions are going to be -4 and 3.
Hope that helps!
-t