1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
sweet-ann [11.9K]
2 years ago
8

At his regular hourly rate, Don had estimated the labor cost of a repair job as $336 and he was paid that amount. However, the j

ob took 4 hours longer than he had estimated and, consequently, he earned $2 per hour less than his regular hourly rate. What was the time Don had estimated for the job, in hours?
(A) 28
(B) 24
(C) 16
(D) 14
(E) 12
Mathematics
1 answer:
Naddika [18.5K]2 years ago
3 0

Answer:

The time Don estimated for the job, in hour, is 24 hours

Step-by-step explanation:

Based on his regular hourly rate, Don had estimated :

Estimated cost (C) = $336

Estimated hour of work =x

So, estimated rate in hour (R) = \frac{336}{x}

In fact, it took him 4 hours longer than he estimated, therefore

Factual hour of work = {x+4}

Factual rate in hour (F) = \frac{336}{x+4}

He earned $2 less than his regular hourly rate, hence the factual rate (F) is the subtraction of estimated rate (R) by 2

F = R - 2

Then, substitute F and R,

\frac{336}{x+4} = \frac{336}{x} - 2

\frac{336}{x+4}+2  = \frac{336}{x}

x(\frac{336}{x+4}+ \frac{2(x+4)}{x+4}) = 336

x(336+2(x+4))  = 336 (x+4)

336x+2x^{2} +8x = 336x+336*4

since at the both sides have 336x, we can removed it.

2x^{2} + 8x = 336 * 4

devide both sides by 2, thus

x^{2} +4x = 336 * 2

x^{2} +4x = 672

Make the algebra function equal to 0 by moving the 672 to the left side.

x^{2} +4x - 672 = 0

factorize the function above,

the factor of 672 is 24 and 28, because if it's multiplied it becomes 672 and if it's subtracted equal to 4. since 4x is positive, the higher number (28) should be in positive. Therefore we conclude that

(x+28)(x-24) = 0

x+28=0, x = -28\\x-24=0, x = 24

We takes the positive result, because the time is in positive. so, the estimated time is 24 hours

You might be interested in
Find A if 30% of A equals 30% of 30 plus 30​
qwelly [4]
30+30= 60 if A is 30 percent of 60 A=0.3 x 60
3 0
2 years ago
Read 2 more answers
Is the number -<img src="https://tex.z-dn.net/?f=%5Cfrac%7B13%7D%7B1%7D" id="TexFormula1" title="\frac{13}{1}" alt="\frac{13}{1}
Alenkasestr [34]

Answer:

13/1 = 13 is the only number integer that divides into it, but all numbers that can be fractions are rational numbers, whether decimal or prime they all can be rational.

Step-by-step explanation:

4 0
3 years ago
I’m lazy to do dis please halp me
Olenka [21]
There could be 6 groups of 7 kids, 7 groups of 6 kids, or 14 groups of 4 kids.
56÷7=6 or 56÷4=14.
6 0
3 years ago
Solve: 3(4x-2)is greater than or equal to 7x+19
Irina18 [472]
Answer in the document below.

5 0
2 years ago
Read 2 more answers
A video posted on the internet is becoming very popular, and the total number of views is increasing by 20% every hour. If the v
Ierofanga [76]

Answer:198000 maybe

Sorry if it’s wrong

3 0
2 years ago
Other questions:
  • Quiero resolver problemas se evaluación
    12·1 answer
  • PLEASE HELP! Solve for n. −56n=40
    10·2 answers
  • What percent of 125 is 24
    14·2 answers
  • Plz help, this is for a quiz, <br><br> 32 + (5 − 2) ⋅ 4 − 6 over 3
    12·2 answers
  • Please answer this correctly
    8·2 answers
  • A bag contains 135 marbles some white and some transparent. The ratio of white marbles to transparent ones is 3 : 6. How many wh
    9·1 answer
  • + + = . . Please im on a time limit
    5·2 answers
  • You deposit $600 in an account earning 6% interest compounded annually. How much will you have in the account in 20 years?
    7·1 answer
  • Write down the exact value of cos 30
    7·1 answer
  • Help me pls thank you<br>​
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!