What is the standard form of #y= (x-3)(x^3-5)*3x^4-5#?

1 Answer
Oct 17, 2017

In standard form
#color(white)("XXX")y=3x^8-9x^7-15x^5+45x^4-5#

Explanation:

# underbrace((x-3)(x^3-5)) * 3x^4-5#

#= underbrace((x^4-5x-3x^3+15) * (3x^4))-5#

#=underbrace((3x^8-15x^5-9x^7+45x^4)-5)#

#=3x^8-15x^5-9x^7+45x^4-5#

To write this in standard form the terms must be arranged in descending degree (where degree is the sum of all variable exponents in the term)
#{: (ul("term"),color(white)("xxxx"),ul("degree")), (3x^8,,8), (-15x^5,,5), (-9x^7,,7),(45x^4,,4), (-5,,0) :}#

Arranged in decreasing degree order:
#y=3x^8-9x^7-15x^5+45x^4-5#