Question

How do I solve the following (^2 means that 2 is the exponent) 7a^2-17a-3a^2+2a

Answer 1

There are like terms in this problem. It looks scary but if we combine our like terms it makes it a lot easier. Also, like terms are terms with the same variables that are at the same power. 

So add 7a^2 and -3a^2

You'll get the following sum: 
4a^2

Add -17a and 2a 

You'll get the following sum: 
-15a

So our new problem looks like this: 

4a^2 - 15a = 0 

Factor out the variable "a." Leaving you with this: 

We can rewrite the problem like this: 
4a^2 - 15a + 0 = 0 

Now we can use the quadratic equation!

$\frac{-b \frac{+}{-} \sqrt{b^2-4ac} }{2a}$

Where +/- is simply the add or divide symbol. Now let's plug in our numbers!

$\frac{-(-15) \frac{+}{-} \sqrt{(-15)^{2}-4*4*0} }{2*4}$

Simplifying a bit you get the following function: 
$\frac{15 \frac{+}{-} \sqrt{225} }{8}$

sqrt(225) = 15

15 + 15 = 30
30 / 8 = 15/4

15 - 15 = 0
0 / 8 = 0 

Your two answers are: 
15/4 and 0