Wize High School Grade 9 Math Textbook > Polynomial Expressions

Dividng a Polynomial by a Monomial
When dividing a polynomial by a monomial, we divide the coefficients and divide the variables separately.

Dividing a monomial by a monomial
Simplify the following:
a) 8x2−2x\dfrac{8x^2}{-2x}−2x8x2​

=8−2x2x=\dfrac{8}{-2}\dfrac{x^2}{x}=−28​xx2​

=−4x=-4x=−4x

b) −12x2y3−9x2y\dfrac{-12x^2y^3}{-9x^2y}−9x2y−12x2y3​

=−12−9x2x2y3y=\dfrac{-12}{-9}\dfrac{x^2}{x^2}\dfrac{y^3}{y}=−9−12​x2x2​yy3​

=43y2=\dfrac{4}{3}y^2=34​y2

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Dividing a polynomial by a monomial
Simplify the following:

a) 6x2−15x3x\dfrac{6x^2-15x}{3x}3x6x2−15x​

=6x23x+−15x3x=\dfrac{6x^2}{3x}+\dfrac{-15x}{3x}=3x6x2​+3x−15x​

=2x−5=2x-5=2x−5

b) (16y−8y2)÷6y(16y-8y^2)\div6y(16y−8y2)÷6y

=16y−8y26y=\dfrac{16y-8y^2}{6y}=6y16y−8y2​

=16y6y+−8y26y=\dfrac{16y}{6y}+\dfrac{-8y^2}{6y}=6y16y​+6y−8y2​

=83−4y3=\dfrac{8}{3}-\dfrac{4y}{3}=38​−34y​

Practice: Dividing a Polynomial by a Monomial.
Simplify −4x2+22x−2x\dfrac{-4x^2+22x}{-2x}−2x−4x2+22x​.

Answer

I don't know

Practice: Dividing a Polynomial by a Monomial
A rectangle has area 25b−15b2+5ab325b-15b^2+5ab^325b−15b2+5ab3. If one of the side lengths is 5b5b5b, find an expression that represents the other side length.

Answer

I don't know