How do you factor 2x^-21x+40 ?

gabriellegabrielle
in Education & Reference

I really need help with this! I have a test coming up next week and knowing how to solve this would really help! Also after solving this I need help setting it equal to zero and solving.

Update:

I need help with this by the end of today PLEASE!

Comments

  • simple-mansimple-man

    I'll try to make it as simple as I can

    2 x 40 =80

    Find 2 numbers which when you multiply gives you 80 and when you add (or subtract) gives you -21

    the 2 numbers are : -16 and -5 because (-16x-5)=80 and (-16-5) =-21

    **There is an error in your question:you forgot the power of 2'**

    So, 2x^2 -21x+40 =2x^2 -16x-5x+40

    =>2x(x-8) -5(x-8)

    =>(2x-5) (x-8)<--

    Now ,if the equation is set to 0

    =>(2x-5) (x-8) =0

    either 2x-5=0 or x-8=0

    either 2x=5 or x=8

    either x=5/2 or x=8 <--

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