New!
Get regular updates about newly solved problems
via algebra.com's RSS system.
Recent problems solved by 'Nate'
Nate answered: 3498 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379 , 1380..1409 , 1410..1439 , 1440..1469 , 1470..1499 , 1500..1529 , 1530..1559 , 1560..1589 , 1590..1619 , 1620..1649 , 1650..1679 , 1680..1709 , 1710..1739 , 1740..1769 , 1770..1799 , 1800..1829 , 1830..1859 , 1860..1889 , 1890..1919 , 1920..1949 , 1950..1979 , 1980..2009 , 2010..2039 , 2040..2069 , 2070..2099 , 2100..2129 , 2130..2159 , 2160..2189 , 2190..2219 , 2220..2249 , 2250..2279 , 2280..2309 , 2310..2339 , 2340..2369 , 2370..2399 , 2400..2429 , 2430..2459 , 2460..2489 , 2490..2519 , 2520..2549 , 2550..2579 , 2580..2609 , 2610..2639 , 2640..2669 , 2670..2699 , 2700..2729 , 2730..2759 , 2760..2789 , 2790..2819 , 2820..2849 , 2850..2879 , 2880..2909 , 2910..2939 , 2940..2969 , 2970..2999 , 3000..3029 , 3030..3059 , 3060..3089 , 3090..3119 , 3120..3149 , 3150..3179 , 3180..3209 , 3210..3239 , 3240..3269 , 3270..3299 , 3300..3329 , 3330..3359 , 3360..3389 , 3390..3419 , 3420..3449 , 3450..3479 , 3480..3509, >>NextTravel_Word_Problems/35514: I can't figure out these questions.
It is approximately 480 miles from Los Angeles, CA, to San Francisco, CA. Allowing for various traffic conditions, a driver can average approximately 60 miles per hour.
Write a linear function that expresses the distance treveled, d, as a function of time, t.
How far have you traveled after 4 hours?
Write a linear function that expresses the distance to b e traveled to reach San Francisco, s as a function of time, t. 1 solutions
Answer 21663 by Nate(3500) on 2006-04-29 12:07:56 (Show Source):
You can put this solution on YOUR website!Write a linear function that expresses the distance treveled, d, as a function of time, t.
t=d/60
How far have you traveled after 4 hours?
d=60t
d=60(4)
d=240 miles
Write a linear function that expresses the distance to be traveled to reach San Francisco, s as a function of time, t.
t=480-60x where x is the hours you already traveled
|
expressions/35512: This question is from textbook Beginning Algebra
1. 5(x-3)+ 5= 3(x+2)-4
2. 3/4(x-2)+ 3/5= 1/5(x+1)
3. one-third of sum of a number and seven 1 solutions
Answer 21662 by Nate(3500) on 2006-04-29 11:55:56 (Show Source):
You can put this solution on YOUR website!1. 5(x-3)+ 5= 3(x+2)-4 original
5x - 15 + 5 = 3x + 6 - 4 distribute
5x - 10 = 3x + 2
2x = 12
x = 6
............................................
2. 3/4(x-2)+ 3/5= 1/5(x+1) original
(3/4(x-2)+ 3/5= 1/5(x+1))20 multiply the whole equation by 20 to delete fractions
15(x-2) + 12 = 4(x+1)
15x - 30 + 12 = 4x + 4
11x - 18 = 4
11x = 22
x = 2
...........................................
3. one-third of sum of a number and seven
For this equation, what does (1/3)(x+7) equal?
|
Graphs/35513: This question is from textbook Beginning Algebra
1. ax + by = c Solve for x.
2. Four less nine times a number is one hundred twenty-two. Find the original number.
1 solutions
Answer 21661 by Nate(3500) on 2006-04-29 11:51:03 (Show Source):
You can put this solution on YOUR website!1. ax + by = c Solve for x.
ax + by = c original
ax = -by + c subtract by from each side
x = (-by + c)/a divide each side by 'a'
........................................
2. Four less nine times a number is one hundred twenty-two. Find the original number
9x-4=122 original equation
9x = 126 add four
x = 14 divide by nine on each side
|
Graphs/35506: Can someone please help me understand graph's before my final next week.
I have 2 questions.
1) It shows a graph given by a quadratic function of the form
f(x)=ax^2, which of these 3 functions matches. The graph shows
a staight line going thru Y at (-2,2) & (2,2)
A)f(x)=2x^2
B)f(x)=3x^2
C)f(x)=1/2x^2
____________________________________
2) It shows a graph is froma quadratic function of the form
f(x)=(x-h)^2 with a symmetry x=-3 and vertex (-3,0). Which
of these 3 matches.
A)f(x)=(x-3)^2
B)f(x)=(x+3)^2
C)f(x)=(x+2)^2
Thanks for all your help
1 solutions
Answer 21656 by Nate(3500) on 2006-04-29 11:12:50 (Show Source):
|
Functions/35505: This question is from textbook
Let f(x) = 2x + 1 and g(x) = x^2 - 4 and find the following:
(fg)(x)
(g of f)(x) 1 solutions
Answer 21652 by Nate(3500) on 2006-04-29 10:54:42 (Show Source):
You can put this solution on YOUR website!f(x) = 2x + 1
g(x) = x^2 - 4
........................................................................
(fg)(x)=(2x+1)(x^2-4)=2x^3+x^2-8x-4
...................................
(g of f)(x) = (2x+1)^2 - 4
= (2x+1)(2x+1) - 4 = 4x^2 + 4x + 1 - 4 = 4x^2 + 4x - 3
|
Functions/35507: This question is from textbook
For the following problems, y varies directly with x
If y is -3 when x is 5, find y when x is -10. 1 solutions
Answer 21649 by Nate(3500) on 2006-04-29 10:50:25 (Show Source):
|
Functions/35508: This question is from textbook
For the following problems y varies inversely with the square of x.
If y is 4 when x is 5, find y when x is 2.
1 solutions
Answer 21645 by Nate(3500) on 2006-04-29 10:45:50 (Show Source):
|
Functions/35503: This question is from textbook
Let f(x) = 2x^2 - 4x + 1 and g(x) = 3x + 2 and evaluate each of the following:
g(f)
f[g(0)]
f[g(1)] 1 solutions
Answer 21642 by Nate(3500) on 2006-04-29 10:39:28 (Show Source):
You can put this solution on YOUR website!g(x) = 3x + 2
f(x) = 2x^2 - 4x + 1
...............................................................
g(f) = 3(2x^2 - 4x + 1) + 2
g(f) = 6x^2 - 12x + 3 + 2
g(f) = 6x^2 - 12x + 5
................................
f[g(0)]=3(0) + 2=2
f(2)=2(4) - 4(2) + 1=1
................................
f[g(1)]=3(1) + 2=5
f(5)=2(25) - 4(5) + 1 = 50 - 20 + 1 = 31
|
logarithm/35404: Hi! I need help with two problems. (^ means exponent follows)
2e^2x = 5^x+1
and...
log(x+1)-log(x)=2
thanks! 1 solutions
Answer 21585 by Nate(3500) on 2006-04-28 23:12:38 (Show Source):
You can put this solution on YOUR website!2e^(2x) = 5^(x+1)
e^(2x) = 5^(x+1)/2
2x = (x+1)ln(5)-ln(2)
2x = 1.6x + 1.6 - 0.69
0.4x = 0.91
x=2.275
The number is about 2.275
.............................................................................
log(x+1)-log(x)=2
log((x+1)/x))=2
(x+1)/(x)=100
x+1=100x
1=99x
x=(1/99)
|
Graphs/35475: For the function, y=1/(x-2)
a) Give the y values for x = -2, -1, 0, 1, 2, 3.
Answer:
Show work in this space.
b) Using these points, draw a curve.
Show graph here. 1 solutions
Answer 21584 by Nate(3500) on 2006-04-28 23:06:06 (Show Source):
You can put this solution on YOUR website!y=1/(x-2)
(-2,-.25),(-1,-.333333),(0,-.5),(1,-1),(2,undefined)
Since I do not know how to show this graph, just connect the dots on a cartesian coordinate plane. It should look like an exponential growth.
|
Graphs/35474: 3) It is approximately 480 miles from Los Angeles, California, to San Francisco, California. Allowing for various traffic conditions, a driver can average approximately 60 miles per hour.
a) Write a linear function that expresses the distance traveled, d, as a function of time, t.
Answer:
b) How far have you traveled after 4 hours?
Answer:
Show work in this space.
c) Write a linear function that expresses the distance to be traveled to reach San Francisco, s, as a function of time, t.
Answer:
Show work in this space.
d) How far will I need to travel to reach San Francisco after I have traveled 3 hours?
Answer:
Show work in this space: 1 solutions
Answer 21583 by Nate(3500) on 2006-04-28 23:01:30 (Show Source):
You can put this solution on YOUR website!a.) Write a linear function that expresses the distance traveled, d, as a function of time, t.
d=60t
b.) How far have you traveled after 4 hours?
d=60t
d=60(4)
d=240
c.) Write a linear function that expresses the distance to be traveled to reach San Francisco as a function of time, t.
t=480/s where s is your speed
d.) How far will I need to travel to reach San Francisco after I have traveled 3 hours?
480 - (3*60) = d
300=d
|
Graphs/35468: This question is from textbook algebra for college students
I need help with this too, Please:
Find the vertex, focus, and directrix of the given parabloa and sketch it's graph:
Find the equation of the parabloa that has it's vertex at (2,-3) and it's focus at (2,-5). 1 solutions
Answer 21582 by Nate(3500) on 2006-04-28 22:48:13 (Show Source):
You can put this solution on YOUR website!distance from vertex to focus (p=1/4a units)
2=1/(4a)
8a=1
a=(1/8)
Directrix: y=-1
Latus Rectum: 1/(A) = (8) units long
use: y=a(x-h)^2+k where the vertex is (h,k)
y=a(x-2)^2-3 also, use the point(-2,-5)
-5=a(-2-2)^2-3
-5=a(-4)^2-3
-2=16a
a=(-1/8)
y=(-1/8)(x-2)^2-3
|
Graphs/35469: This question is from textbook algebra for college students
I need help with this too, Please:
Find the vertices, the endpoints of the minor axis, and foci of the given ellipse, and sketch it's graph:
4x squared + y squared - 8y + 4y + 4 = 0 1 solutions
Answer 21580 by Nate(3500) on 2006-04-28 22:36:56 (Show Source):
You can put this solution on YOUR website!4x^2 + y^2 - 8y + 4y + 4 = 0
4x^2 - 8x + y^2 + 4y = -4
4(x^2 - 2x) + (y^2 + 4y) = -4
4(x - 1)^2 + (y + 2)^2 = 4
((x - 1)^2) + ((y + 2)^2)/4 = 1
center (1,-2)
has a vertical major axis
a(length of major axis) = 2
b(length of minor axis) = 1
c^2 = a^2 - b^2
c^2 = 4 - 1
c = 3^(1/2) or -3^(1/2) length cannot be negative so the c is 3^(1/2)
foci: (1+3^(1/2),-2) and (1-3^(1/2),-2)
|
Exponential-and-logarithmic-functions/35470: I'm really struggling with this problem:
The amount of radioactive material, in grams, present after t days is modeled by
A(t)=500e to the -0.05t (-0.05t is the exponent)
a)What is the initial amount of material?
b)How much material is left after 10 days?
c)Find the half-life of the material. 1 solutions
Answer 21578 by Nate(3500) on 2006-04-28 22:28:13 (Show Source):
You can put this solution on YOUR website!a.)A(t)=500e^(-0.05t)
A(0)=500(1)
Initially, the amount was 500 grams.
b.)A(t)=500e^(-0.05t)
A(10)=500e^(-0.5)
Since I do not have a calculator with 'e', I'll let you solve the rest.
c.)250=500e^(-.05t) the end result is half of the initial (500) so (250)
.5 = e^(-.05t)
ln .5 = -.05t take the natural log of each side
(ln .5)/(-.05) = t
The time for half life of the radioactive element is about 13.86 days.
|
Graphs/35472: This question is from textbook algebra for college students
I need help with this too, Please:
Find the vertices, the endpoints of the minor axis, and foci of the given ellipse, and sketch it's graph:
(x+5) squared + 4(y-4) squared = 16 1 solutions
Answer 21577 by Nate(3500) on 2006-04-28 22:22:12 (Show Source):
You can put this solution on YOUR website!(x+5)^2 + 4(y-4)^2 = 16 original
((x+5)^2)/16 + ((y-4)^2)/4 = 1 divide by 16 to get the side to equal 1
the major axis is the highest value (16)^(1/2)
the major axis is 4 units long, and the major axis is horizontal
the minor axis, on the other hand, is the lower value (4)^(1/2)
the minor axis is 2 units long
the center is found by: ((x-h)^2)/a^2 + ((y-k)^2)/b^2 = 1
where a is the length of the minor axis and b is the length of the minor axis and (h,k) is the center
the center is (-5,4)
...................................................................
To Graph: go to the point (-5,4) and make points 4 units left and right of that point....also, go 2 units up and down from the center....connect the dots (excluding the center) to make an ellipse
|
logarithm/35274: In a town whose population is 2000, a disease creates an epidemic. The number of people (N) infected (t) days after the disease has begun is given by the function N(t)=2000/(1+19e^-0.6t) a. how many are initially infected with the disease (t=0)? b. how many infected after 2,5,8,12, and 16 days? 1 solutions
Answer 21574 by Nate(3500) on 2006-04-28 22:14:28 (Show Source):
You can put this solution on YOUR website!N(t)=2000/(1+19e^-0.6t)
N(0)=2000/(1+19(1))
N(0)=2000/(20)
N(0)=100
Initially, 100 people were infected.
--------------------------------------------
N(t)=2000/(1+19e^-0.6t)
N(2)=2000/(1+19e^(-1.2))
I do not have a calculator on me, so I will let you solve the rest of the equation. Also, all you have to do is plug in the numbers into your calculator, and you will have it all solved. I'll let you finish.
|
absolute-value/35464: This question is from textbook algebra for college students
Can anyone tell me how to: Find an equation of the circle with center (4,-3) and radius 5. I need to express the final equation in the form x squared + y squared + Dx + Ey + F = 0 1 solutions
Answer 21570 by Nate(3500) on 2006-04-28 22:05:48 (Show Source):
You can put this solution on YOUR website!the equation for a circle is:
(x-h)^2 + (y-k)^2 = r^2 where center is (h,k) and r is the radius
with center (4,-3) and radius 5
(x - 4)^2 + (y + 3)^2 = 25
x^2 - 8x + 16 + y^2 + 6y + 9 - 25 = 0
x^2 + y^2 - 8x + 6y = 0
|
Equations/35383: Here what the used was only the symbol of pi but I don't know how to write that using the keyboard so I wrote the actual word "pi."
Classify the given number as real and rational, real and irrational, or complex.
pi 1 solutions
Answer 21553 by Nate(3500) on 2006-04-28 21:43:48 (Show Source):
|
Graphs/35420: I need to solve the equation 4x + y > 4 then determine the half plane which I would show on the graph. I am lost at how to do this. 1 solutions
Answer 21550 by Nate(3500) on 2006-04-28 21:39:51 (Show Source):
You can put this solution on YOUR website!put into y=mx+b where m is the slope and b is the y-intercept
4x + y > 4
y > -4x + 4
slope is -4
y-intercept is 4
*The answer is all numbers higher than the line*
| Solved by pluggable solver: DESCRIBE a linear EQUATION: slope, intercepts, etc |
Equation describes a sloping line. For any
equation ax+by+c = 0, slope is .- X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x = c/a. 4/4 = 1.
- Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 4/1 = 4.
- Slope is -4/1 = -4.
- Equation in slope-intercept form: y=-4*x+4.
|
|
Graphs/35459: Please help. I go to college online and I have to submit this answer by Sat. night.Heres the question:
x -2 -1 0 1 2
y .0625 .25 1 4 16
Given the table above, graph the function, identify the graph of the function (line, parabola, hyperbola, or exponential), explain your choice, and give the domain and range as shown in the graph, and also the domain and range of the entire function.
Graph:
Graph Type:
Explanation:
Domain:
Range:
1 solutions
Answer 21538 by Nate(3500) on 2006-04-28 20:46:32 (Show Source):
You can put this solution on YOUR website!the numbers decrease as the x-values go lower....but the y-values never
are equal to or lower than 0 .... so it must be an exponential function!
use y=(a)(b^x)
y=(a)(b^x)
1=a(b^0)
a=1
so: y=b^x
4=b^1
b=4
so your final equation is:
y=4^x
------------------------------------
the domain and range are the same as in the graph as they are in your list
domain: all real number
range: y>0
sorry, I do not know how to plot an exponential growth equation to show you
|
Triangles/35424: hello I have 2 questions i was assigned to draw and label each figure
a. an isooscelees traingle with area equal to 32 square inches.
b. A trapezoid with area equal to 50 square inches.
may you please help me
thank you 1 solutions
Answer 21536 by Nate(3500) on 2006-04-28 20:39:20 (Show Source):
You can put this solution on YOUR website!a.)the area fora circle is (1/2)(l)(w)
(1/2)(l)(w)=32
(1/2)x^2=32 the sides are equal
x^2=64
x = 8 or -8 a side cannot be negative so the sides are 8 inches while the
hypontenuse is (8192)^(1/2) which is about 90.5 inches
b.)((parallel + parallel)/2)h = area of trapezoid
((parallel + parallel)/2)h = 50
depends on what you want the length of the parallel lines
let us say that the top parallel line is 30 and the bottom parallel line is 20
(((20)+(30))/2)h = 50
(25)h = 50
h = 2
|
Parallelograms/35458: This question is from textbook Geometry
The area of a parallelogram is 2x^2 + 9x + 4 cm^2
If the length of the base is 2x + 1 cm, find the length of the altitude.
1 solutions
Answer 21534 by Nate(3500) on 2006-04-28 20:27:13 (Show Source):
You can put this solution on YOUR website!the area of a parallelogram is the base times height
a=lh
here, we want to find h so:
h=a/l
h=(2x^2 + 9x + 4)/(2x + 1)
h=(x + 4)
|
Volume/35431: How do I find the volume of a cone that has a circumfrence at the base of 100 feet and its height is 14 feet high. 1 solutions
Answer 21533 by Nate(3500) on 2006-04-28 20:21:21 (Show Source):
You can put this solution on YOUR website!The equation to find the volume for a cone is: V=(1/3)(area of base)(height)
100=2(3.14)(x) where x is the radius for the cirmuference of the base
(100)/((2)(3.14))=x
the radius is about 15.92
V=(1/3)(area of base)(height)
V=(1/3)((15.92)^2(3.14))(14))
V=3,717.38 feet cubed
|
Geometric_formulas/35442: If possible, descibe a geometric figure that can be transformed into itself by each of the following:
reflection
rotation
translation
glide reflection 1 solutions
Answer 21532 by Nate(3500) on 2006-04-28 20:10:21 (Show Source):
|
|