What is the standard form of # y= (x - 40) (x + 4) #?
1 Answer
Jan 3, 2016
#y=x^2-36x-160#
Explanation:
If you like, you can use FOIL to help multiply this out:
#y = (x-40)(x+4)#
#= stackrel "First" overbrace(x*x) + stackrel "Outside" overbrace(x*4) + stackrel "Inside" overbrace(-40*x) + stackrel "Last" overbrace(-40*4)#
#=x^2+4x-40x-160#
#=x^2-36x-160#
