How do you factor #2x^2-5x+2#?

3 Answers
Dec 13, 2017

#=(2x-1)(x-2)#

Explanation:

Ok, we are just going to factor this one out!

#=2x^2-5x+2#

Break it into groups

#=(2x^2-x)+(-4x+2)#

At this point we can factor out x and -2 respectively

#=x(2x-1)-2(2x-1)#

Then factor out the common term

#=(2x-1)(x-2)#

Hope this helped!
~Chandler Dowd

Dec 13, 2017

#(2x-1)(x-2)#

Explanation:

#"the factors of + 4 which sum to - 5 are - 4 and - 1"#

#"splitting the middle term"#

#2x^2-4x-x+2larrcolor(blue)"factor by grouping"#

#=color(red)(2x)(x-2)color(red)(-1)(x-2)#

#"take out "color(blue)"common factor "(x-2)#

#=(x-2)(color(red)(2x-1))#

#rArr2x^2-5x+2=(x-2)(2x-1)#

Dec 13, 2017

#(2x -1)(x-2)#

Explanation:

#color(magenta)(2)x^2 -color(blue)(5)x color(red)(+)color(lime)(2)#

All the information is in the trinomial.

Find the factors of #color(magenta)(2) and color(lime)(2)# which #color(red)("ADD")# to make #color(blue)(5)#

The #color(red)(+)# sign gives two clues:

  • ADD the factors to get the middle number
  • the sign in the brackets will be the SAME.

Note that #2 xx 2=4" " and 1xx1 =1#

Now #4+1=5#, so #2 and 2# are the factors.
As #2# is a prime number there are only two ways of combining the factors.

SO know we know:

#(2x" "1)(x" "2)#

We also know the signs will be the SAME.

The sign of the middle term #color(blue)(-5)# shows they will be negative.

#(2x -1)(x-2)#

Check by multiplying:

#=2x^2 -4x-1x+2#

#=2x^2 -5x+2#