I NEED URGENT ASSISTANCE
8. is the following statement always, never, or sometimes true?
a number is raised to a negative exponent is negative?
A always
B never
C sometimes
9 simplify(4xy^2)^3(xy)^5
A 64x^8 y^11
B 64x^15 y^30
C 12x^2 y^11
D 12x^8 y^11
10 simplify(2t^-3)^3(0.4r)^2
a 3.2r^2
b 1.28r^2/ t^-6
c 1.28r^2/ t^9
d 0.8r^2/ t^-6

Respuesta :

Answer:

8 C sometimes

9 64x^8 y^11

10 c 1.28r^2/ t^9

Step-by-step explanation:

Algebraic Operations

Some basic rules must be fresh in our minds when trying to simplify complex algebraic expressions. For example, the power rule respect to the product or quotient:

[tex]\displaystyle \left(\frac{x^n.y^m}{z^p}\right)^q= \frac{x^{qn}.y^{qm}}{z^{qp}}[/tex]

[tex]\displaystyle \frac{x^n.x^q}{x^p}= x^{n+q-p}[/tex]

[tex]\displaystyle x^{-n}=\frac{1}{x^n}[/tex]

Let's face the questions at hand

8. A number is raised to a negative exponent is negative?

Following the expressions recalled above, let's pick the expression

[tex]\displaystyle 3^{-2}=\frac{1}{3^2}=\frac{1}{9}[/tex]

This is a negative power resulting in a positive number

Now we pick

[tex]\displaystyle (-2)^{-3}=\frac{1}{(-2)^3}=-\frac{1}{8}[/tex]

This time, the negative power leads to a negative result, so it doesn't matter the sign of exponent to determine the sign of the result

Answer: C sometimes

9 simplify(4xy^2)^3(xy)^5

[tex](4xy^2)^3(xy)^5=4^3x^3(y^2)^3x^5y^5[/tex]

[tex]=64x^3y^6x^5y^5[/tex]

[tex]=64x^8y^{11}[/tex]

10 simplify(2t^-3)^3(0.4r)^2

[tex](2t^{-3})^3(0.4r)^2=2^3(t^{-3})^30.4^2r^2[/tex]

[tex]=8t^{-9} 0.16 r^2[/tex]

[tex]=1.28t^{-9} r^2[/tex]

[tex]\displaystyle \frac{1.28 r^2}{t^9}[/tex]