Select the correct answer. Simplify the following expression. Classify the resulting polynomial.

3x(x − 3) + (2x + 6)(-x − 3)

quadratic monomial

quadratic binomial

quadratic trinomial

linear binomial

quadratic trinomial

Step-by-step explanation:

3x(x − 3) + (2x + 6)(-x − 3)

Distribute

3x^2 -9x  + (2x + 6)(-x − 3)

FOIL

3x^2 -9x   + -2x^2 -6x -6x -18

Combine like terms

x^2-21x-18

This has 3 terms so it is a trinomial

The highest power of x is 2 so it is quadratic

9514 1404 393

Step-by-step explanation:

Eliminating parentheses, we get ...

  = (3x)(x) -(3x)(3) +(2x)(-x -3) +6(-x -3)

  = 3x² -9x +(2x)(-x) +(2x)(-3) +(6)(-x) +(6)(-3)

  = 3x² -9x -2x² -6x -6x -18

  = x²(3 -2) +x(-9-6-6) -18

  = x² -21x -18

The highest power is 2, so this is a quadratic.

There are 3 terms, so this is a trinomial.

12

step-by-step explanation:

a triangle's   full angle is 180 degrees so 180 - 156 = 24. 24/2=12

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it