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3 years ago

Evaluate the expression when a=-6 and c= 2 . a-4c

Mathematics

2 answers:

Harman [31]3 years ago

5 0

Answer:

-14

Step-by-step explanation:

a-4c=(-6)-4(2)=-6-8=-14. Hope this helps!

BartSMP [9]3 years ago

3 0

Answer:

-14

Step-by-step explanation:

(-6) - 4(2)

(-6) - 8

-14

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Let f(x)= 12/4x+2 find f(-1)

denis23 [38]

F(x) = 12/(4x+2)

x = -1

f(-1) = 12 / [4(-1)+2]

f(-1) = 12 / (-4+2)

f(-1) = 12 / -2

f(-1) = -6

5 0

3 years ago

The two polygons above are similar. The scale factor of the smaller polygon to the larger polygon is 3. The area of the smaller

Softa [21]

You would think it was 3 * 12 = 36. Not so. All polygons have to be broken down into some figure that will give 2 dimensions that are at right angles to each other. That would mean that
d1 * d2 = Area for the small polygon
3d1 * 3d2 = area of the larger polygon

What that means is that the area of the larger one is 9 times the smaller one.
Area large = 12 * 9 = 108 square units. <<<<< answer.

If you find this hard to be leave try it with a square.
Suppose you have a square (the small one) that is 3 cm by 3 cm
The small one has an area of 3*3 cm^2 = 9 cm

Now you have another square that is 3 times larger. That means that each side is 3*3 = 9
So s = 9
Area = s^2
Area = 9^2 = 81 cm^2
81 is 9 times larger than 9 just as you would think.

4 0

3 years ago

Luke has two summer jobs. During the week he works in the grocery store, and on the

TiliK225 [7]

Hello! First, let's get some important information:

Luke works in the:

week → grocery store → $16/hour
weekend → nursery → $22/hour

Now, let's analyze the questions:

<h3>a) How much does he earn if he works 5 hours at the grocery store and 8 hours at the nursery? </h3>

To find the amount he will receive, you must multiply the amount of 1 hour by the number of hours worked. Look:

$\mathrm{Grocery\:Store}\\\\\$16 \cdot 5 \:\mathrm{hours}= \$80\\\$22 \cdot 8\:\mathrm{hours}=\$176$

<h3>b) How much does he earn if he works g hours at the grocery store and n hours at the nursery?</h3>

$\$16 \cdot \mathrm{g} \:\mathrm{hours}= \$16\cdot\mathrm{g}\\\$22 \cdot \mathrm{n}\:\mathrm{hours}=\$22\cdot\mathrm{n}$

<h3>c) Total pay, 5 hours at the grocery store and 8 hours at the nursery:</h3>

You'll just have to just add the value in each of the jobs:

$80 + $176 = $256

<h3>d) Total pay, g hours at the grocery store and n hours at the nursery:</h3>

Adding the values of each job:

$16g + $22n

Hope this helps!

8 0

3 years ago

Find the area of the trapozoid.

Bad White [126]

Area =

$\frac{1} {2} \times sum \: of \: parallel \: sides \: \times height$

=》

$\frac{1}{2} \times (6 + 10) \times 5$

=》

$\frac{1}{2} \times 16 \times 5$

=》

$8 \times 5$

=》

$40$

Area = 40 in²

5 0

3 years ago

Read 2 more answers

Find constants a and b such that the function y = a sin(x) + b cos(x) satisfies the differential equation y'' + y' − 5y = sin(x)

vichka [17]

Answers:

a = -6/37

b = -1/37

============================================================

Explanation:

Let's start things off by computing the derivatives we'll need

$y = a\sin(x) + b\cos(x)\\\\y' = a\cos(x) - b\sin(x)\\\\y'' = -a\sin(x) - b\cos(x)\\\\$

Apply substitution to get

$y'' + y' - 5y = \sin(x)\\\\\left(-a\sin(x) - b\cos(x)\right) + \left(a\cos(x) - b\sin(x)\right) - 5\left(a\sin(x) + b\cos(x)\right) = \sin(x)\\\\-a\sin(x) - b\cos(x) + a\cos(x) - b\sin(x) - 5a\sin(x) - 5b\cos(x) = \sin(x)\\\\\left(-a\sin(x) - b\sin(x) - 5a\sin(x)\right) + \left(- b\cos(x) + a\cos(x) - 5b\cos(x)\right) = \sin(x)\\\\\left(-a - b - 5a\right)\sin(x) + \left(- b + a - 5b\right)\cos(x) = \sin(x)\\\\\left(-6a - b\right)\sin(x) + \left(a - 6b\right)\cos(x) = \sin(x)\\\\$

I've factored things in such a way that we have something in the form Msin(x) + Ncos(x), where M and N are coefficients based on the constants a,b.

The right hand side is simply sin(x). So we want that cos(x) term to go away. To do so, we need the coefficient (a-6b) in front of that cosine to be zero

a-6b = 0

a = 6b

At the same time, we want the (-6a-b)sin(x) term to have its coefficient be 1. That way we simplify the left hand side to sin(x)

-6a -b = 1

-6(6b) - b = 1 .... plug in a = 6b

-36b - b = 1

-37b = 1

b = -1/37

Use this to find 'a'

a = 6b

a = 6(-1/37)

a = -6/37

8 0

3 years ago