Ask question

Ask question

All categories

2 years ago

9

A computer repair company charges a $10 fee to come to your house to fix your computer plus $25 per hour while they are there. W

hat is x, the number of hours they could charge in order for your total cost to be at least $150?

1 answer:

gogolik [260]2 years ago

5 0

150 divided by 25 is 6, so I think it would be 6 hours to equal the total cost.

You might be interested in

What is the gcf of 24 30 42

olga55 [171]

GCF(24, 30, 42) = 6 I think it is.

6 0

3 years ago

Read 2 more answers

a winery has a vat with two pipes leading to it. the inlet pipe can fill the vat 7 hours, while the outlet pipe can empty it in

raketka [301]

Lets say, for ease, that the vat can hold a total of 70 gallons (or whatever you would like to use.) Use whatever number you want, I just picked this because it gives us a lot of clean numbers.

Now, if the inlet can fill it in 7 hours, that means that it is adding 10 gallons per hour. (70 gal/7 hours = 10 gal/hr)

For the outlet, use the same process, and you find that it drains the vat at 7 gallons per hour.

So, if you subtract the outlet from the inlet, you get 10 - 7 = 3 gallons per hour added.

Now just divide the size of the vat by that number, and you find your answer.

70 gallons / 3 gallons per hour = 23 1/3 hours.

6 0

3 years ago

Deangelo has $7 worth of dimes and quarters in a jar. He has 7 more quarters than dimes.

svlad2 [7]

D=number of dimes
q=number of quarters

let's count everything in cents
dimes are worth 10 cents
quarters are worth 25 cents

10d+25q=700
divide both sides by 5
2d+5q=140

he has 7 more quarters than dimes
q=7+d
subsitute 7+d for q in other equation

2d+5q=140
2d+5(7+d)=140
2d+35+5d=140
7d+35=140
minus 35 both sides
7d=105
divide both sides by 7
d=15

sub back

q=7+d
q=7+15
q=22

22 quarters and 15 dimes

3 0

3 years ago

Read 2 more answers

A poll found that 53% of a sample of 1170 teens in a certain large country go online several times a day. (Treat this sample as

posledela

Answer:(a) margin error = 2.4%

(b) The margin error gives the measure in percentage of how the population parameter determined differ from the real population statistics or value.

(c) in 90% of the samples of teens in the country, the percent who go online several times a day will be within 50.6% and 55.4%. of the estimated 100%

Step-by-step explanation:

Using the proportion formulae

Margin error = z √p(1-p)/n

n= 1170, p = 53% = 0.53, 1-p = 0.47

and the z value at 90% C.I = 1.645

M error= 1.645 √0.53×0.47/1170

Margin error = 0.024 = 0.024 ×100

Margin error = 2.4%

53 - 2.4 = 50.6% and 53 + 2.4 = 55.4%

In other words 90% of the time: the number of teens who go online several time a day will be between 50.6 and 55.4%.

8 0

3 years ago

!!! HELP ME !!!

antoniya [11.8K]

Answer:

DHGB

Step-by-step explanation:

Let's start with 1.

The equation is in standard form (ax+by=c): -4x+2y=8

we'll put it into slope intercept form.

Add 4x onto both sides

2y=4x+8

divide by 2

y=2x+4

Parallel lines have the same slope, but a different y intercept. (the line parallel to this one will have a slope of 2 but a y intercept different from +4)

Looking at the answer choices, the only choice with a slope of 2 is D (y=2x-5)

So the answer to 1 is D

Now 2.

we're given 3 points. One of the points crosses the y axis, which is the y intercept. In this case, the line crosses the point (0,3)

That means the y intercept of the line is (0,3)

here's the line so far:

y=mx+3 (m is a placeholder for the slope)

when given a graph, we can use rise/run. Starting from the point (3,2), we can move 3 spaces to the left, and one up.

In a graph, if you move to the left or downwards, it's a negative move. If you move up or to the right, it's a positive move.

Since we went 1 space up (rise) and 3 spaces to the left, (run) the slope is -1/3

So the line is y=-1/3x+3

Perpendicular lines are negative and reciprocal. If you multiply their slopes, they will equal -1. Their y intercepts don't matter at all.

So to find the slope, we can use this equation.

-1/3m=-1

multiply by -3 on both sides

m=3

Looking at the answer choices, H is the only answer with a slope of 3. So the answer to 2 is H.

Now, 3

You can do the graph method like above for 2, but I'll just calculate the slope.

We're given two points, (-1,-2) and (0,2)

the formula for slope is (y2-y1)/(x2-x1)

we can label the points.

x1=-1

y1=-2

x2=0

y2=2

now, substitute into the equation.

m=(2--2)/(0--1)

m=4/1

the slope is 4.

Now let's use point slope form, which is y-y1=m(x-x1)

once again, sub. into the equation.

y+2=4(x+1)

do distributive prop

y+2=4x+4

subtract by 2

y=4x+2

As said above, parallel lines have the same slope.

Looking at the answer options, G also has the slope of 4

so the answer to 3 is G

Finally, #4

Equation: 3x+y=1

subtract 3x from both sides

y=-3x+1

As said above, perpendicular lines have slopes that multiply to equal -1.

-3m=-1

multiply by -1/3

m=1/3

so the slope of the line will be 1/3.

Looking at the answer options, B also has a slope of 1/3.

So the answer to 4 is B

The code is DHGB

Hope this helps!

4 0

3 years ago