(picture) multiplying monomials and binomials

Second option: 81y^4 - 16x^2, the difference of squares

Step-by-step explanation:

(9y^2-4x)(9y^2+4x) is a special product named difference of squares, then we can apply this formula:

(a-b)(a+b)=a^2-b^2, with a=9y^2 and b=4x, then:

(9y^2-4x)(9y^2+4x)=(9y^2)^2 - (4x)^2

(9y^2-4x)(9y^2+4x)=(9)^2 (y^2)^2 - (4)^2 (x)^2

(9y^2-4x)(9y^2+4x)=81y^(2*2) - 16x^2

(9y^2-4x)(9y^2+4x)=81y^4 - 16x^2

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.

1. d.90

2. e. none of these (80)

3. a. 0

4. b. 6

5. e. none of these (10)

6. a. 5