Homework Help

# 4/9w^2+1=5/3w  solve by factoring

eNoter

• Up
• 0
• Down

4/9w^2+1=5/3w  solve by factoring

Posted by tdt3 on July 31, 2013 at 7:48 PM via web and tagged with math, quadratic formula

High School Teacher

(Level 1) Educator Emeritus

• Up
• 1
• Down

Solve `4/9 w^2+1=5/3 w` :

`4/9 w^2-5/3 w+1=0`  It is easier if you multiply through by 9 to clear the fractions:

`4w^2-15w+9=0` We seek two numbers whose product is 36 and whose sum is -15 -- the numbers are -12 and -3

`4w^2-3w-12w+9=0`

`w(4w-3)-3(4w-3)=0`

`(4w-3)(w-3)=0`  Using the zero product property:

`4w-3=0 ==> w=3/4`  and w-3=0 ==> w=3

----------------------------------------------------------------

The two solutions are `w=3/4,w=3`

---------------------------------------------------------------

Posted by embizze on July 31, 2013 at 9:19 PM (Answer #2)

eNoter

• Up
• 0
• Down

change the improper fractions into whole numbers by multiplying everything by 9.

the function becomes

4w^2+9=15w

it now becomes easier to solve. Put everything on one side

4w^2-15w+9=0

4w^2-12w-3w+9=0

4w(w-3)-3(w-3)=0

(4w-3)(w-3)=0

therefore w=3 and w=3/4

Posted by mufarochamu on July 31, 2013 at 8:33 PM (Answer #1)