How do you write (5x^2 - 4x + 5) (3x^2 - 6x + 2)(5x24x+5)(3x26x+2) in standard form?

1 Answer
Jan 17, 2017

15x^4-42x^3+49x^2-38x+1015x442x3+49x238x+10

Explanation:

We must ensure that each term in the second bracket is multiplied by each term in the first bracket. This is illustrated below.

(color(red)(5x^2-4x+5))(3x^2-6x+2)(5x24x+5)(3x26x+2)

=color(red)(5x^2)(3x^2-6x+2)color(red)(-4x)(3x^2-6x+2)=5x2(3x26x+2)4x(3x26x+2)
color(white)(xxxx)color(red)(+5)(3x^2-6x+2)××+5(3x26x+2)

distributing gives.

15x^4-30x^3+10x^2-12x^3+24x^2-8x+15x^2-30x+1015x430x3+10x212x3+24x28x+15x230x+10

collecting like terms.

15x^4+(-30-12)x^3+(10+24+15)x^2+(-8-30)x+1015x4+(3012)x3+(10+24+15)x2+(830)x+10

=15x^4-42x^3+49x^2-38x+10larr" in standard form"=15x442x3+49x238x+10 in standard form

Writing in standard form means, start with the term of the highest power of the variable, followed by terms with decreasing powers of the variable.