Question

A rectangle has sides measuring (6x + 4) units and (2x + 11) units. Part A: What is the expression that represents the area of the rectangle? Show your work. (4 points) Part B: What are the degree and classification of the expression obtained in Part A? (3 points) Part C: How does Part A demonstrate the closure property for polynomials? (3 points)

Answer 1

Answer:

Step-by-step explanation:

Part A:

A=lw

A=(6x + 4)*(2x + 11)

multiply it out:

A=6x*2x+6x*11+4*2x+4*11

A=12x^(2)+66x+8x+44

add like terms

A=12x^(2)+66x+8x+44

A=12x^(2)+(66+8)x+44

A=12x^(2)+74x+44

the expression used to find area is 12x^(2)+74x+44

Part B:

this is:

a second degree trinomial

since its leading coefficient (highest degree value of the expression) is 2

and

since it has three monomials (terms that are separated by + or - signs):

12x^(2)+74x+44

Part C:

(not sure about this one)

all area is positive or 0 (no area), so lets find the values of x that are true:

lets find the zeros

(6x + 4)*(2x + 11)=0

6x+4=0

6x=-4

x=-4/6

x=-2/3

2x+11=0

2x=-11

x=-11/2

6*(-11/2)+4

3*(-11)+4

-33+4

-29

2*(-2/3)+11

-4/3+33/3

29/3

6*(-2/3) + 4

2*(-2)+4

-4+4

0

x is greater than (-2/3)

Thus, any real number greater than -2/3 makes

(6x + 4)*(2x + 11) equals the expression:

12x^(2)+74x+44, where x is a real number greater than -2/3

if lets say x= 1, a counting number then:

(6*1 + 4)*(2*1 + 11)=12*1^(2)+74*1+44

(6+4)*(2+11)=12*1+74+44

10*13=12+118

130=130

130 and 1 are both counting numbers, proving the closure property of polynomials

Answer 2

Answer:

Step-by-step explanation:

A:

(6x + 4)*(2x + 11)

12x^2+8x+66x+44

12x^2+74x+44

B:

a second degree polynomial

C:

The closure property for polynomials can be demonstrated here if you put in some # like a whole number and get an answer that is whole too:

(6x + 4)*(2x + 11)=12x^2+74x+44

if x=0

(6*0 + 4)*(2*0 + 11)=12*0^2+74*0+44

4*11=12*0+0+44

44=44

both 0 and 44 are whole numbers, hence proving the closure property