how to solve step by step using quadratic formula

Question

x²+3x=5

Answer 1

Hello, Britt again.

 

ok.. The first we need to do is to rewrite  the problem into the standard form: ax^2+bx+c=0. So,

X^2 +3x     =5           Subtract 5 from both sides

              -5   -5

x^2  +3x  -5 = 0       a=1, b=3, c= -5

 

Now, We are going to use the Quadratic Formula

 

{-(b) +/- [sq. rt. (b^2-4ab)]}/2a    

 

What I am going to do is do the Determinant:  which is b^2-4ac, using a=1, b=3 and c= -5

(3)^2-4(1)(-5)

9+ 20 = 29           Don't forget it is sq. rt. of 29

 

Following the formula

 

x= [-3+ sq. rt. 29]/ 2             or  x= [-3 - sq. rt. 29]/2

 

If you want you can find the square root of 29 which is 5.385164.  Let's round to 5.39

I let you finish it... they are about to close the library.

 

Again, it is a pleasure to help out.

 

D. Y. Taylor