Which of the following must be true for and expression to be a difference of two squares?
a. both coefficients are perfect squares.
b. there are only two terms.
c. both terms have negative coefficients.

The correct options are:

(A)Both coefficient are perfect squares.

(B)There are only two terms.

Step-by-step explanation:

A difference of two square means the both numbers in the given equation has to be the square numbers.

Hence , the difference of two squares with more then two terms will never be there.

Now, if the example is taken as the expression , Here we can take the square of both the term easily and separately.

Hence, the correct options are:

(A)Both coefficient are perfect squares.

(B)There are only two terms.

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d. $180

step-by-step explanation:

if the dimensions of the room is 9ft by 12 ft, we have the area of the floor as,

so the area of the floor is 108 square feet, converting that into square yards we get,

the cost of carpet is $15 per square yard, therefore the cost of carpet for 12 square yards is,

hence, the cost of carpet is $180.

assuming the dimensions of the room be,

15 ft by 12 ft

so, the area of the floor of that room is,

we can convert 180 square feet into square yards, we know that,

1 sq ft = 0.111 sq yard

so, 180 square feet is,

so the area of floor is 20 square yards.

now, the cost of carpet is 15 dollars per square yard, therefore the cost of carpet for 20 square yards is,

so, it will cost $300.

answer: 486in^2

step-by-step explanation: