guys i really need some help, no matter how hard I try i really can't understand how to solve quadratic equations. can you guys help me? can you guys give me some easy and hard questions and then explain how to solve it? i am applying for college again so please a help would be appreciated!!!

Question
Answer:
First there are  equations that are solved by factoring. 

Easy example:-   x^2 + 2x + 8 = 0

You need to find 2 numbers whose product = last number 8 and when added gives the coefficient of x ( that is 2)

+4 and +2 will do this so the factors are 

(x + 4)(x + 2) = 0
Now either x + 4 = 0 or x + 2 = 0
solving these 2 simple equations we get the answer:-
x = -4 ,  -2.

If we had a number  before the term in x^2 its more complicated:-

2x^2 + 5x - 7 = 0

First multiply coefficient of x by the last term - 7:-
2 * -7  = -14
Now we need 2 factors of -14 which gives us  the middle coefficient + 5.
+7 and -2 look good so we write:-
2x^2 - 2x + 7x - 7 = 0
Now we factor by grouping the first 2 and the last 2 terms:-
2x(x - 1) + 7(x - 1) = 0
(x - 1) is common to both parts so we have:-
(2x + 7)(x - 1) = 0
Now we can solve this 

2x + 7 = 0  or x - 1 = 0

x = 3.5, 1

Other types of quadratic are solved by the quadratic formula or by  completing the square.

If you want some practice try solving:-

1. x^2 + 2x + 24 = 0


2.  3x^2 + 3x  -18 = 0





solved
general 6 months ago 7093