What is the standard form of #y= (4x-5)(x-4) #?

1 Answer
Jan 8, 2016

#y = 4x^2-21x+20#

Explanation:

You can use the FOIL mnemonic to help multiply this out:

#y = (4x-5)(x-4)#

#=stackrel "First" overbrace((4x*x)) + stackrel "Outside" overbrace((4x*-4)) + stackrel "Inside" overbrace((-5*x)) + stackrel "Last" overbrace((-5*-4))#

#=4x^2-16x-5x+20#

#=4x^2-21x+20#

Standard form puts the powers of #x# in descending order.