Question

Question 1 (1 point)

Answer 1

Answer:

1) $2y^{2}+4y-9$

2) $18x^{5}y^{4}z$

3) $6x^{5}-12x^{4}+9x^{3}$

4) 40

5) $x^{3}-7x^{2}+3x+36$

Step-by-step explanation:

1) Distribute the negative sign that is outside the parentheses and then you must add like terms, as following:

$(y^{2}-3y-5)-(-y^{2}-7y+4)=y^{2}-3y-5+y^{2}+7y-4=2y^{2}+4y-9$

2) According to the Product property of exponents, when you multiply powers with the same base, you must add the exponents. Then:

$(6xy^{3}z)(3x^{2}yx^{2})=18x^{5}y^{4}z$

3) Apply the Distributive property and the Product property of exponents. Then, you obtain:

$-3x^{3}(-2x^{2}+4x-3)=6x^{5}-12x^{4}+9x^{3}$

4) $(4a+5)^{2}$ is a square of a sum, then, by definition you have:

$(a+b)^{2}=a^{2}+2ab+b^{2}$

Then:

$(4a+5)^{2}=(4a)^{2}+2(4a)(5)+5^{2}=16a^{2}+40a+25$

The coefficient of the second term is the number in front of the variable a. Then, the answer is: 40

5)  Apply the Distributive property and the Product property of exponents, then, oyou must add the like terms:

$(x-4)(x^{2}-3x-9)=x^{3}-3x^{2}-9x-4x^{2}+12x+36=x^{3}-7x^{2}+3x+36$