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4 years ago

13

Please help me with this math problem

2 answers:

gogolik [260]4 years ago

4 0

Answer: (z+2)(z-9)

Step-by-step explanation:

$z^{2} -7z-18$ to solve for this you need to find two numbers that if multiplied together they give you negative 18 and at the same time adds up to -7.

Those two numbers could be -9 and 2 .

now rewrite the expression like this.

$z^{2} +2z - 9z -18$ Group them

( $( z^{2} +2z) ( -9z- 18)$ Factor it out z in the first grouping

z(z +2) -9(z + 2) factor out x+2

(z +2 ) (z-9)

erik [133]4 years ago

3 0

Answer:

(z-9)(z+2)

Step-by-step explanation:

U have to find numbers which when u multiply u get -18 and subtract u get -7

-18= -9×+2,2-9=-7

Z²+2z-9z-18

Z(z+2)-9(z+2)

(Z-9)(z+2)

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Natalia is making a pizza. The radius of the pizza is 25 inches. What is

aniked [119]

(b)(b)=25 cm2

b2=25 cm2

√(b2)=√(25 cm2)

b= 5 cm

Please note the square root of 25 was taken, as well as the square root of cm2.

Perimeter=4b

Perimeter=4(5 cm)

Perimeter=20 cm

Step:

A circle of radius = 12.5 or diameter = 25 or circumference = 78.54 cm has an area of: 4.909 × 10-8 square kilometers (km²) 0.04909 square meters (m²)

8 0

3 years ago

Please help me! I’m not good at math

Mazyrski [523]

This is my answer. Good luck!

5 0

3 years ago

Write a quadratic function whose zeros are -3 and -4

andreev551 [17]

Answer:

f(x) = (x -(-3))(x -(-4))

Step-by-step explanation:

The function can be written as the product of binomial terms whose values are zero at the given zeros.

(x -(-3)) is one such term

(x -(-4)) is another such term

The product of these is the desired quadratic function. In the form easiest to write, it is ...

f(x) = (x -(-3))(x -(-4))

This can be "simplified" to ...

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6 0

4 years ago

6x8-6x5 in distributive property.

ddd [48]

Answer:

6(8 -5)

Step-by-step explanation:

take out the 6 -

8 - 5

then put them in parentheses

(8 - 5)

add back the 6

6(8 - 5)

8 0

3 years ago

Read 2 more answers

You have been asked to design a can shaped like right circular cylinder that can hold a volume of 432π-cm3. What dimensions of t

rosijanka [135]

Answer:

$Height = 12cm$

$Radius = 6cm$

Step-by-step explanation:

Given

Represent volume with v, height with h and radius with r

$V = 432\pi$

Required

Determine the values of h and r that uses the least amount of material

Volume is calculated as:

$V = \pi r^2h\\$

Substitute 432π for V

$432\pi = \pi r^2h$

Divide through by π

$432 = r^2h$

Make h the subject:

$h = \frac{432}{r^2}$

Surface Area (A) of a cylinder is calculated as thus:

$A=2\pi rh+2\pi r^2$

Substitute $\frac{432}{r^2}$ for h in $A=2\pi rh+2\pi r^2$

$A=2\pi r(\frac{432}{r^2})+2\pi r^2$

$A=2\pi (\frac{432}{r})+2\pi r^2$

Factorize:

$A=2\pi (\frac{432}{r} + r^2)$

To minimize, we have to differentiate both sides and set $A' = 0$

$A'=2\pi (-\frac{432}{r^2} + 2r)$

Set $A' = 0$

$0=2\pi (-\frac{432}{r^2} + 2r)$

Divide through by $2\pi$

$0= -\frac{432}{r^2} + 2r$

$\frac{432}{r^2} = 2r$

Cross Multiply

$2r * r^2 = 432$

$2r^3 = 432$

Divide through by 2

$r^3 = 216$

Take cube roots of both sides

$r = \sqrt[3]{216}$

$r = 6$

Recall that:

$h = \frac{432}{r^2}$

$h = \frac{432}{6^2}$

$h = \frac{432}{36}$

$h = 12$

Hence, the dimension that requires the least amount of material is when

$Height = 12cm$

$Radius = 6cm$

3 0

3 years ago