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drk answered: 1901 problems
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Answer 194137 by drk(1908) on 2010-01-31 14:29:49 (Show Source):
You can put this solution on YOUR website!Normally we want

where m = slope and b = y-intercept.
in our example we have

which means

or m = 0 and b = -8/5.
to graph
first plot -8/5 on the y-axis.
second move up 0 and over 1 (rise / run) and place a dot.
connect the dots to find a long horizontal line.
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Evaluation_Word_Problems/263438: Given G(t) = 4 − 7t, write G( 5 + h) − G(5) in simplest form. 1 solutions
Answer 194132 by drk(1908) on 2010-01-31 14:26:33 (Show Source):
You can put this solution on YOUR website!the problem is
Given G(t) = 4 − 7t, write G(5 + h) − G(5) in simplest form.
step 1 - replace t with 5+h to get
G(5+h) = 4 - 7(5+h)
distribute to get
G(5+h) = 4 - 35 -7h
combine like terms to get
G(5+h) = -7h - 31
---
G(5) = 4 - 7*5 = 4 - 35 = -31
---
G(5+h) - G(5) = -7h - 31 - (-31) = -7h
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Evaluation_Word_Problems/263440: The sum of two numbers is 39. The greater number is 5 less than 3 times the smaller number. What are the two numbers? 1 solutions
Answer 194131 by drk(1908) on 2010-01-31 14:23:47 (Show Source):
You can put this solution on YOUR website!We
(i) a + b = 35
(ii) a = 3b - 5
substituting (ii) into (i), we get
(iii) 3b-5 + b = 35
combine like terms to get
(iv) 4b - 5 = 35
adding 5 we get
(v) 4b = 40
dividing, we get
b = 10
so
a = 25
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Mixture_Word_Problems/263434: A silversmith mixed 30 g of a 70% silver alloy with 50 g of a 15% silver alloy. What is the percent concentration of the resulting alloy? (Round your answer to the nearest tenth of a percent.) 1 solutions
Answer 194129 by drk(1908) on 2010-01-31 14:21:43 (Show Source):
You can put this solution on YOUR website!This is a mixture problem with out mixture information. Here is a table based on the given information
alloy . . . . . .% . . . . . .g . . . . . . .%g
70 . . . . . . . 70 . . . . 30 . . . . . .2100
15 . . . . . . .15 . . . . .50 . . . . . .750
mix . . . . . . x . . . . . .80 . . . . . .80x
looking at the third column, we get

adding we get

dividing, we get
x = 35.625
which is
35.63% = 35.6%
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Age_Word_Problems/263432: In 1992 the life expectancy of males in a certain country was 66.2 years in 1997 it was 69.9 years let E represent the life expectancy in year t and let t represent the number of years since 1992? 1 solutions
Answer 194127 by drk(1908) on 2010-01-31 14:16:48 (Show Source):
You can put this solution on YOUR website!I think you are looking for a linear equation to model this data. We have two coordinates here
(0, 66.2) and (5, 69.9). Let 1992 = 0 and 1997 = 5.
step 1 - find the slope using

to get

which is

---
step 2 - using y = mx + b, and a coordinate, we get

so,

---
we have our answer as
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Linear-systems/263429: Determine whether the system is consistent, inconsistent, or dependent.
3x - 3y = -9
9x - 9y = -27
Determine whether the system is consistent, inconsistent, or dependent.
2x + 2y = 2
6x + 6y = 6 1 solutions
Answer 194125 by drk(1908) on 2010-01-31 14:12:57 (Show Source):
You can put this solution on YOUR website!Lets take these one at a time:
Determine whether the system is consistent, inconsistent, or dependent.
(i) 
(ii) 
step 1 - multiply (i) by -3 to get
(iii) 
step 2 - add (ii) and (iii) to get
(iv) 
Here we have dependent , consistent
Determine whether the system is consistent, inconsistent, or dependent.
(i) 
(ii) 
step 1 - multiply (i) by -3 to get
(iii) 
step 2 - add (ii) and (iii) to get
(iv) 
Here we have dependent , consistent
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Mixture_Word_Problems/263426: A butcher has some hamburger that is 29% fat and some that is 15% fat. How many pounds of each should be mixed to make 63 lb of hamburger that is 17% fat? 1 solutions
Answer 194124 by drk(1908) on 2010-01-31 14:07:35 (Show Source):
You can put this solution on YOUR website!This is a mixture problem. Here is a table based on the given information
fat . . . . . . .% . . . . . . pounds . . . . . . . . %-pounds
29. . . . . . . 29 . . . . . . . .p . . . . . . . . . . .29p
15 . . . . . . .15 . . . . . . . .63-p. . . . . . . . .945 -15p
17 . . . . . . .17 . . . . . . . .63. . . . . . . . . . .1071
set the third column equal to get

combine like terms to get

subtract 945 to get

p = 9 pounds @ 29 %
63-p = 54 pounds @ 15%
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Mixture_Word_Problems/263420: A ferry leaves a harbor and travels to a resort island at an average speed of 22 mph. On the return trip, the ferry travels at an average speed of 10 mph because of fog. The total time for the trip is 4 h. How far is the island from the harbor? 1 solutions
Answer 194122 by drk(1908) on 2010-01-31 14:01:23 (Show Source):
You can put this solution on YOUR website!This is an RTD problem. Here is a table based on the given information
location . . . . . rate . . . . .time . . . . . distance
resort . . . . . . . .22 . . . . .t. . . . . . . . . . 22t
harbor . . . . . . .10 . . . . .4-t. . . . . . . . . 40-10t
total. . . . . . . . . . . . . . . . 4
since distances are =, set

add 10t to get

divide by 32 to get
 hours
we want distance, so
22*1.25 = 27.5 miles
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Travel_Word_Problems/263413: Henry can ride his horse at 4 miles per hour and get to the battlefield on time. If he stops for 1 hour to make a speech to his troups, he must ride 5 miles per hour for the whole trip to get to the battlefield on time. How far is it to the battlefield? 1 solutions
Answer 194119 by drk(1908) on 2010-01-31 13:56:55 (Show Source):
You can put this solution on YOUR website!This is an RTD problem. Here is a table based on the given information
travel . . . . . rate . . . . . .time . . . . . .distance
horse . . . . . . 4 . . . . . . . .t . . . . . . . . .4t
speech . . . . . 5 . . . . . . . t-1 . . . . . . . 5t - 5
set

subtract 5t to get

so
t = 5.
distance = 4t = 20 miles
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Polynomials-and-rational-expressions/263411: Factor the expression on the left side of each equation. Then solve the equation
4x³-32=0 1 solutions
Answer 194116 by drk(1908) on 2010-01-31 13:30:49 (Show Source):
You can put this solution on YOUR website!The original equation was

step 1 - rewrite the left side as

and then using difference of cubes, we get

set each part = 0 and solve to get

add 2^(5/3) to get

divide by 4^(1/3) to get

the other parentheses, trinomial, will generate imaginary answers. so we get
x = 2.
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Rate-of-work-word-problems/263393: An 8 hp pump can fill a tank in 8 hours. A smaller 3 hp pump fills the same tank in 12 hours. The pumps are used together to begin filling this tank. After four hours, the 8 hp pump breaks down. How long will it take the smaller pump to fill the tank? 1 solutions
Answer 194114 by drk(1908) on 2010-01-31 13:20:30 (Show Source):
You can put this solution on YOUR website!This is a working together problem.
The rate of the 8 hp pump = 1/8
the rate of the 3 hp pump is 1/12
The time together will be 4 hours.
The time that the 3 hp pump works alone is x hrs.
We want to fill only 1 tank
-----
we use the formula

we get

adding the fractions, we get

subtract 5/6 to get

multiply by 12 to get

So, the 3 hp pump must work and additional 2 hours.
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Rectangles/263394: What is the perimeter and area of the rectangle that is 33 m wide and 2 m long? 1 solutions
Answer 194109 by drk(1908) on 2010-01-31 13:14:20 (Show Source):
You can put this solution on YOUR website!Perimeter formula is

area formula is

---
from the given information, we get
 }

P = 70 m
---
from the given information, we get

A = 66 meters squared.
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Miscellaneous_Word_Problems/263404: If the patterns of the fines continue at the same rate of increase at what speed will the fines be the same? Given: County A rate is +15, County B rate is +10; at 60mph fine for County A is $0 and the fine for County B is $40. 1 solutions
Answer 194107 by drk(1908) on 2010-01-31 13:11:30 (Show Source):
You can put this solution on YOUR website!If I understand the question correctly, we have two equations
(i) 
(ii) 
setting them equal, we get

distribute to get

combine like terms to get

subtract 10m and add 900 to get

divide to get

So, at 68 mph,
city A fine will be $120
city B fine will be $120
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Linear-equations/263407: Solve the following system of linear equations. If possible, express your answer as an ordered pair (x,y). Also, tell whether the system of equations is “independent”, “inconsistent”, or “dependent”.
2x-4y=8
x-2y=4
1 solutions
Answer 194103 by drk(1908) on 2010-01-31 13:02:09 (Show Source):
You can put this solution on YOUR website!Here is our original system
(i) 
(ii) 
step 1 - multiply (ii) by -2 to get
(iii) 
add (ii) and (iii) to get
(iv) 
this mans that we have the same equations but in disguise.
These equations are "dependent"
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Number-Line/263397: cant seem to solve this one.. i have to put it on a number line too
x^2 + 2x > 3
Thanks! 1 solutions
Answer 194099 by drk(1908) on 2010-01-31 12:55:55 (Show Source):
You can put this solution on YOUR website!here is the original question

step 1 - subtract 3 to get

step 2 -factor to get

step 3 we need to create 3 number line graphs. Make sure the 0 marker is aligned in all three.
number line graph #1:
x+3> 0
this means open circle above -3 and then + signs to the right and - signs to the left.
number line graph #2:
x-1> 0
this means open circle above +1 and then + signs to the right and - signs to the left.
number line graph #3:
(x+3)(x-1) > 0
we place open circles above -3 and then +1.
To the left of -3, we have - signs for both lines. - x - = + so in the third number line place a + to the left of -3.
Between -3 and +1 we have different signs, so place a - sign on the third number line between -3 and +1.
To the right of +1, we have + signs for both lines. + x + = +, so in the third number line place a + to the right of +1.
we want where the signs are > 0 or the + regions.
Our final answer is
open circles above -3 and +1 and then arrow from the -3 to the left and arrow from the +1 to the right.
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Triangles/263396: Two sides of a triangle have the same length. The third side measures 4 m less than twice that length. The perimeter of the traiangle is 24 m. Find the lengths of the 3 sides. 1 solutions
Answer 194097 by drk(1908) on 2010-01-31 12:43:13 (Show Source):
You can put this solution on YOUR website!Let x be the length of each equal side and then 2x - 4 is the length of the base.
p = a + b + c
24 = a + b + c

step 1 - combine like terms to get

step 2 - add 4 to get

step 3 - divide by 4 to get

the three sides are
{7, 7, 10}
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Mixture_Word_Problems/263387: What values are excluded from the domain of the function? (Separate multiple answers with commas. Enter NONE if there are none.)
F(x) = (3 x - 9)/(x - 8) 1 solutions
Answer 194093 by drk(1908) on 2010-01-31 12:31:45 (Show Source):
You can put this solution on YOUR website!To determine the domain of any function, we ask 2 questions
(1) is the variable in a square root of any type?
if "yes" set the stuff under the root >= 0 and solve for x.
if "no" go to question 2.
(2) is the variable information in the denominator?
if "yes" set the denominator stuff not = 0 and solve for x.
if "no" then you say "all reals"
-----
Using these questions on the given problem., we get
(1) NO
(2) YES
so

solving for x, we get
x = 8.
This means we cannot use x = 8 as a domain number.
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Square-cubic-other-roots/263378: Verify that -2 is a root of the equation 
Find the other two roots, correct to 2 decimal places. 1 solutions
Answer 194089 by drk(1908) on 2010-01-31 12:20:15 (Show Source):
You can put this solution on YOUR website!we can use synthetic division to verify. This will generate another equation that we will factor.
-2 // . . . 2 . . . . 1 . . . . -10 . . . . . -8
. . . . . . . . . . . . -4 . . . . .6 . . . . . . .8
. . . . . . . 2 . . . . -3 . . . . -4 . . . // . 0
So, we have verified by getting a 0 remainder. We now have a new equation of the form

By quadratic, we get

and then

we have two answers and rounded, we get
x ~ 2.35
x ~ -0.85
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real-numbers/263369: Cant seem to figure this one out :/
Find all solutions of the equation and express them in the form (a+bi)
2x^2 - 2x + 3 = 0 1 solutions
Answer 194086 by drk(1908) on 2010-01-31 12:12:06 (Show Source):
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real-numbers/263370: Find all solutions of the equation and express them in the form (a+bi)
z + 4 + 12/z = 0
Thanks :) 1 solutions
Answer 194083 by drk(1908) on 2010-01-31 12:07:18 (Show Source):
You can put this solution on YOUR website!here is our original equation:

step 1 - multiply by z to get

using the quadratic, we get

which becomes

and then

canceling, we get
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