Easy Algebra Step-by-Step

168 Easy Algebra Step-by-Step

When you’re identifying coeffi cients for

ax^2 ++bxbx c= 0 , keep a − symbol with

the number that follows it.

Problem Solve by using the quadratic formula.

a. 32 xx^2222 x+ 11 = 0

b. 22 xx^222 x− 50

c. xx^2696 xx = 0

Solution

a. 32 xx^2222 x+ 11 = 0

Step 1. Identify the coeffi cients a, b, and c

and then use the quadratic formula.

ab,,bbbb=− 22 and cc= 11

x

bbac

a

=

−b −

=

(^24) −^2 −
2

± 4

2

()− 2 ()− 2 () 3 () 11

() 3

=

24 ± − 132

6

=

2 ±− 128

6

Step 2. State the solution.

Because the discriminant is negative there is no real number solu-

tion for 32 xx^2222 x+ 11 = 0.

b. 22 xx^222 x− 50

Step 1. Identify the coeffi cients a, b, and c and then use the quadratic

formula.

ab,,bbbb= 22 and c=− 5

x

bbac

a

=

−b −

=

(^24) − (^2) −
2

± 4

2

() 2 () 2 () 2 ()− 5

() 2

=

− 24 ± + 40

4

=

− 24 ± 4

4