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lwsshak3 answered: 6517 problems
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logarithm/619762: please help me solve this equation
2 log base 5 radical 5
1 solutions

Answer 391499 by lwsshak3(6519) About Me  on 2012-06-21 03:14:24 (Show Source):
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solve this equation
2 log base 5 radical 5
2log5(√5)
=2log5(5^1/2)
=log5(5^1/2)^2
=log5(5)
=1


test/622651: |2x^2 + 3| = 7x
1 solutions

Answer 391498 by lwsshak3(6519) About Me  on 2012-06-21 02:33:19 (Show Source):
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|2x^2 + 3| = 7x
solve for two conditions:
2x^2+3=7x
2x^2-7x+3=0
(2x-1)(2x-3)=0
x=1/2
or
x=3/2 (reject, does not check)
..
2x^2+3=-7x
2x^2+7x+3=0
(2x+1)(2x+3)=0
x=-1/2 (reject, does not check)
or
x=-3/2 (reject, does not check)
solution: x=1/2


test/622650: Two number differ by 5 and 3/5 of the greater number is equal to 3/4 to the smaller. Find the number.
1 solutions

Answer 391496 by lwsshak3(6519) About Me  on 2012-06-21 02:15:07 (Show Source):
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Two number differ by 5 and 3/5 of the greater number is equal to 3/4 to the smaller. Find the number
**
let x=larger number
x-5=smaller number
3x/5=3(x-5)/4
3x/5=(3x-15)/4
LCD=20
12x=15x-75
3x=75
x=25
x-5=20
larger number=25
smaller number=20


Coordinate-system/622592: Find the x and y intercepts and graph the equation plotting the intercepts. Please show all of your work. -4x+9y=-36

1 solutions

Answer 391494 by lwsshak3(6519) About Me  on 2012-06-21 02:02:59 (Show Source):
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Find the x and y intercepts and graph the equation plotting the intercepts. Please show all of your work. -4x+9y=-36
y-intercept
set x=0
9y=-36
y=-4
..
x-intercept
set y=0
-4x=-36
x=4
see graph below:
+graph%28+300%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C4x%2F9-4%29+


Polynomials-and-rational-expressions/622644: Please help! Find the LCD.
+%28%285%29%2F%287ab%5E5%29%29+and+%28%282%29%2F%287a%5E3b%5E3%29%29+
1 solutions

Answer 391493 by lwsshak3(6519) About Me  on 2012-06-21 01:52:56 (Show Source):
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Find the LCD
((5)/(7ab^5)) and ((2)/(7a^3b^3))
select the highest power of each variable in the denominator
LCD: 7a^3b^5


Polynomials-and-rational-expressions/622640: Please help! Multiply.
+%28%288x%5E2%29%2F%28x%5E2-9%29%29%28%28x%5E2%2B6x%2B9%29%2F%2816x%5E3%29%29+
1 solutions

Answer 391492 by lwsshak3(6519) About Me  on 2012-06-21 01:47:46 (Show Source):
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((8x^2)/(x^2-9))((x^2+6x+9)/(16x^3))
=(8x^2)(x^2+6x+9)/(x^2-9)(16x^3)
=(x+3)^2/(x^2-9)2x
=(x+3)^2/2x(x+3)(x-3)
=(x+3)/2x(x-3)


Polynomials-and-rational-expressions/622641: Please help! Divide.
+%28%283y%2B12%29%2F%288y%5E3%29%29%2F%28%289y%2B36%29%2F%2816y%5E3%29%29+
1 solutions

Answer 391489 by lwsshak3(6519) About Me  on 2012-06-21 01:37:38 (Show Source):
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((3y+12)/(8y^3))/((9y+36)/(16y^3))
=2(3y+12)/(9y+36)
=2*3(y+4)/9(y+4)
=6/9
=2/3


Polynomials-and-rational-expressions/622638: Please help! Simplify completely.
+%28x-2%29%2F%288x%5E2-32%29+
1 solutions

Answer 391486 by lwsshak3(6519) About Me  on 2012-06-21 01:29:07 (Show Source):
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(x-2)/(8x^2-32)
=(x-2)/8(x^2-4)
=(x-2/8(x+2)(x-2)
=1/[8(x+2]


test/622626: solve using long division, then check.
(x^3+2x^2+3x-6)/(x-1)=?
1 solutions

Answer 391485 by lwsshak3(6519) About Me  on 2012-06-21 01:22:50 (Show Source):
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solve using long division, then check.
(x^3+2x^2+3x-6)/(x-1)=?
**
..............x^2......3x.......6.......
...x-1|....x^3....2x^2....3x...-6
........................3x^2....3x......
........................3x^2..-3x......
....................................6x..-6..
....................................6x..-6..
..........................................0..
Check:
quotient*divisor+remainder=dividend
(x^2+3x+6)(x-1)+0
=x^3+3x^2+6x-x^2-3x-6+0
=x^3+2x^2+3x-6


logarithm/622632: which among log (base 13)169 and log (base 23)521 is greater ?(with out using calculator)
thanks

1 solutions

Answer 391483 by lwsshak3(6519) About Me  on 2012-06-21 01:03:35 (Show Source):
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which among log (base 13)169 and log (base 23)521 is greater
Using exponential form of logs:
Base raised to log of number=number
for first case
13^x=169
x=2 which is the log of 169 base 13
..
for 2nd case
23^x=521
x=<2 which is the log of 529 base 23 (if x=2, the number=23^2=529, so x<2)
The log of the first case>log of 2nd case


Percentage-and-ratio-word-problems/622571: A 45 gallon barrel contains a mixture with a concentration of 30%. How much of this mixture must be withdrawn and replaced by 100% concentrate to bring the mixture up to 50% concentration?
1 solutions

Answer 391450 by lwsshak3(6519) About Me  on 2012-06-20 20:26:30 (Show Source):
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A 45 gallon barrel contains a mixture with a concentration of 30%. How much of this mixture must be withdrawn and replaced by 100% concentrate to bring the mixture up to 50% concentration?
**
let x=mixture to be withdrawn and replaced
45-x=remaining 30% mixture
30%(45-x)+100%x=50%*45
13.5-.3x+x=22.5
.7x=9
x≈12.86
gallons of mixture to be withdrawn and replaced≈12.86


Linear-equations/622573: Find the slope Intercept form for the lie satisfying the following condition for x-intercept 2, y-intercept 2/3
1 solutions

Answer 391449 by lwsshak3(6519) About Me  on 2012-06-20 20:11:41 (Show Source):
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Find the slope Intercept form for the lie satisfying the following condition for x-intercept 2, y-intercept 2/3
Standard form of equation for a straight line: y=mx+b, m=slope, b=y-intercept
**
2 given points: (2,0) and (0,2/3)
slope=∆y/∆x=(2/3-0)/(0-2)=(2/3)/-2=-2/6=-1/3
equation:
y=-x/3+b
y=-x/3+2/3


Trigonometry-basics/622016: please help me solve for all
2cos(x/2)+1 =0
1 solutions

Answer 391448 by lwsshak3(6519) About Me  on 2012-06-20 19:51:48 (Show Source):
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solve for all
2cos(x/2)+1 =0
2cos(x/2)=-1
cos(x/2)=-1/2
x/2=2π/3
x=π/3+2πn, n=integer
and
x/2=4π/3
x=2π/3+2πn, n=integer


Trigonometry-basics/622507: please help me verify:
cos^3sin^2= (sin^2-sin^4)cosx
1 solutions

Answer 391440 by lwsshak3(6519) About Me  on 2012-06-20 19:29:33 (Show Source):
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please help me verify:
cos^3sin^2= (sin^2-sin^4)cosx
starting with right side:
(sin^2-sin^4)cosx
=sin^2(1-sin^2)cos
=sin^2*cos^2*cos
=cos^3sin^2
verified:
right side=left side


Trigonometry-basics/622497: please help me find the exact values of:
sin2u
given: sinu= -4/5 and pi < u 3pi/2
1 solutions

Answer 391409 by lwsshak3(6519) About Me  on 2012-06-20 16:28:25 (Show Source):
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find the exact values of:
sin2u
given: sinu= -4/5 and pi < u 3pi/2
sinu=-4/5 in quadrants III and IV where sin<0
since quadrant IV is not in the domain,(π,3π/2), reference angle is in quadrant III
sinu=-4/5=opposite side/hypotenuse
adjacent side=3 since you are working with a 3-4-5 right triangle
cosu=-3/5 in quadrants III where cos<0
sin 2u=2sinucosu
=2*-4/5*-3/5
=24/25


Trigonometry-basics/622024: please help me find the exact value of
tan2u
given: sinu= -4/5 & pi < u < 3pi/2
1 solutions

Answer 391408 by lwsshak3(6519) About Me  on 2012-06-20 16:10:52 (Show Source):
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find the exact value of
tan2u
given: sinu= -4/5 & pi < u < 3pi/2
**
sinu=-4/5 in quadrants III and IV where sin<0
since quadrant IV is not in the domain,(π,3π/2), reference angle is in quadrant III
sinu=-4/5=opposite side/hypotenuse
adjacent side=3 since you are working with a 3-4-5 right triangle
tanu=opposite side/adjacent side=4/3 in quadrant III where tan>0
tan2u=2tanu/(1-tan^2u)=2*4/3/(1-(4/3)^2)=(8/3)/(1-16/9)=(8/3)/(-7/9)=-72/21


Trigonometry-basics/622255: Find all values of θ, if θ is in the interval [0°, 360°) and has the following function value sinθ = - sqrt3/2
1 solutions

Answer 391401 by lwsshak3(6519) About Me  on 2012-06-20 15:49:55 (Show Source):
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Find all values of θ, if θ is in the interval [0°, 360°) and has the following function value sinθ = - sqrt3/2
**
sinθ = -√3/2 in quadrants III and IV where sin<0
reference angle=60º
θ=240º and 300º


Trigonometry-basics/622075: please helpme solve:
add & simplify:
(1/csc(beta)+1)-(1/csc(beta) -1)
1 solutions

Answer 391396 by lwsshak3(6519) About Me  on 2012-06-20 15:37:39 (Show Source):
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please helpme solve:
add & simplify:
(1/csc(beta)+1)-(1/csc(beta) -1)
use x for beta
1/cscx=sinx
(1/cscx+1)-(1/cscx -1)
=(sinx+1)-(sinx-1)
=six+1-sinx+1
=2


Trigonometry-basics/622310: (Sin)sqx+(cos)sqx=1? Why
1 solutions

Answer 391288 by lwsshak3(6519) About Me  on 2012-06-20 04:14:09 (Show Source):
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(Sin)sqx+(cos)sqx=1? Why
Let me try using a right triangle
let o=opposite side
let a=adjacent side
let h=hypotenuse
..
sin=o/h
cos=a/h
sin^2=o^2/h^2
cos^2=a^2/h^2
sin^2+cos^2
=o^2/h^2+a^2/h^2
=(o^2+a^2)/h^2
=1
By Pythagorean Theorem:
The sum of the squares of the two sides=the square of the hypotenuse.
Therefore, (o^2+a^2)/h^2=1


Travel_Word_Problems/622308: Find the quotient and remainder for the division problem (2t3 + 9t2 − 2t − 3) ÷ (2t + 1)
1 solutions

Answer 391287 by lwsshak3(6519) About Me  on 2012-06-20 03:57:00 (Show Source):
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Find the quotient and remainder for the division problem
(2t3 + 9t2 − 2t − 3) ÷ (2t + 1)
**
by long division:
.................t^2.....4t...........................
..2t+1|....2t^3....9t^2....-2t.....-3..............................
...............2t^3......t^2.......................
..........................8t^2...-2t...................
..........................8t^2.....4t.............
.................................. ..-6t.....-3......
Quotient: t^2+4t
Remainder: -6t-3


Polynomials-and-rational-expressions/622295: Find the quotient
y^4-3y+4/ y^2-5
1 solutions

Answer 391285 by lwsshak3(6519) About Me  on 2012-06-20 03:38:59 (Show Source):
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Find the quotient
y^4-3y+4/ y^2-5
By long division:
................ y^2..........5...................
.y^2-5..|...y^4... 0. ..0.. ..3y....4.....................
.................y^4..... ..-5y^2..................
.............................. 5y^2......-25......
.........................................3y..29..
dividend : y^4-3y+4
divisor: y^2-5
quotient: y^2+5+Remainder
Remainder: 3y+29


Travel_Word_Problems/622298: Person A and person B start from the same location, at the same time. They ride their bikes in opposite directions for 3 hours, at which time they are 102 miles apart. person A rides 4 miles per hour faster than person B. Find the rate of each rider.
I am having trouble figuring out the equation. I made a table that looks like this:
D R T
A r+4 3
B r 3
1 solutions

Answer 391283 by lwsshak3(6519) About Me  on 2012-06-20 03:01:53 (Show Source):
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Person A and person B start from the same location, at the same time. They ride their bikes in opposite directions for 3 hours, at which time they are 102 miles apart. person A rides 4 miles per hour faster than person B. Find the rate of each rider.
**
let x=rate of rider B
x+4=rate of rider A
distance=travel time*rate
..
3x+3(x+4)=102
3x+3x+12=102
6x=90
x=15
x+4=19
ans:
rate of rider B=15 mph
rate of rider A=19 mph


Age_Word_Problems/622299: f(x)=(1)/(√(4x^2-17x+4))
Find the domain and express in interval notation
info: its 1 over the square root of the numbers listed above
1 solutions

Answer 391282 by lwsshak3(6519) About Me  on 2012-06-20 02:46:27 (Show Source):
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f(x)=(1)/(√(4x^2-17x+4))
Find the domain and express in interval notation
info: its 1 over the square root of the numbers listed above
**
f(x)=(1)/(√(4x^2-17x+4))
=1/√(4x^2-17x+4)
=1/[√(4x-1)(x-4)]
check for values of x which makes function undefined:
4x-1=0
x≠1/4
or
x-4=0
x≠4
..
check for radican≥0
(4x-1)(x-4)≥0
number line
<..+....1/4....-......4.....+.........>
Domain: (-∞,1/4) U (4,∞)
In other words, all real numbers except x=1/4 and 4 and between x=1/4 and 4 (not including 1/4 and 4)


Graphs/622148: solve the inequality 2x%5E3%2B5x%5E2-17x-20%3C0
1 solutions

Answer 391155 by lwsshak3(6519) About Me  on 2012-06-19 17:16:31 (Show Source):
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solve the inequality
2x^3+5x^2-17x-20<0
To solve this problem, the equation must be in factored form.
This seems like a difficult expression to factor and probably it could be done with the rational roots theorem, but I'm just going to use a graphing calculator to find the following factors of this problem:
2x^3+5x^2-17x-20<0
(x+4)(x+1)(2x-5)<0
number line:
<..-...-4....+.....-1....-....5/2.....+.......>
solution:
(-∞,-4) U (-1,5/2)


Money_Word_Problems/622147: how much money would be in an account after 5 years if an original investment of $6500 was compounded quarterly at 4.5%?. compare this amount to the same investment that was compounded daily. round to the nearest cent.
1 solutions

Answer 391152 by lwsshak3(6519) About Me  on 2012-06-19 16:47:33 (Show Source):
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how much money would be in an account after 5 years if an original investment of $6500 was compounded quarterly at 4.5%?. compare this amount to the same investment that was compounded daily. round to the nearest cent.
**
Compound Interest formula:
A=P(1+i)^n, P=initial investment, i=interest rate per period, A=amount after n periods
For given problem:
compounding quarterly
P=6500
i=.045/4 (annual interest/number of compounding periods per year)
n=5*4=20 periods
A=6500(1+.045/4)^20
using calculator
A=8129.88
..
compounding daily
P=6500
i=.045/365 (annual interest/number of compounding periods per year)
n=5*365=1825 periods
A=6500(1+.045/365)^1825
using calculator
A=8139.98
..
compounding daily gives about $10 more over a 5-year period


Exponents/622138: (1/3)^x=(81)(9^(x-1)) when solving for x is -2/3. I do not know how.
1 solutions

Answer 391146 by lwsshak3(6519) About Me  on 2012-06-19 16:17:25 (Show Source):
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(1/3)^x=(81)(9^(x-1)) when solving for x is -2/3. I do not know how.
**
(1/3)^x=(81)(9^(x-1))
1/(3^x)=(81)(3^2)^(x-1)
3^-x/(81)(3^(2x-2))
3^-x/(3^(2x-2))=81
3^(-3x+2)=3^4
-3x+2=4
-3x=2
x=-2/3
note: when moving from denominator to numerator or vise-versa, sign of exponents change.


absolute-value/620927: how would you solve this problem
|x/5 - 1| = | 1 - x/3|
1 solutions

Answer 391041 by lwsshak3(6519) About Me  on 2012-06-19 03:59:21 (Show Source):
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how would you solve this problem
|x/5 - 1| = | 1 - x/3|
solve for two conditions
(x/5-1)=(1-x/3)
x/5-1=1-x/3
LCD:15
3x-15=15-5x
8x=30
x=30/8
x=15/4
..
and
(x/5-1)=-(1-x/3)
(x/5-1)=-1+x/3)
LCD:15
3x-15=-15+5x
2x=-30
x=-15


absolute-value/621866: how would you solve this problem
|2x - 1| => 1/8
1 solutions

Answer 391040 by lwsshak3(6519) About Me  on 2012-06-19 03:45:44 (Show Source):
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how would you solve this problem
|2x - 1| => 1/8
solve for two conditions:
2x-1≥1/8
multiply by 8
16x-8≥1
16x≥9
x≥9/16
and
-2x+1≥1/8
-16x+8≥1
-16x≥-7
x≤7/16
..
number line
<====7/16]..........[9/16====>
solution:
(-∞,7/16] U [9/16,∞)


absolute-value/621872: how would you solve this problem
4<6+2/3x < 8
1 solutions

Answer 391039 by lwsshak3(6519) About Me  on 2012-06-19 03:33:01 (Show Source):
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how would you solve this problem
4<6+2/3x < 8
4<6+2/3x < 8
add-6
-2<2/3x<2
multiply by 3
-6<2x<6
divide by 2
-3 < x <3
number line:
<.......(-3<===>3)........>
solution:
(-3,3)


absolute-value/621873: |2x+6| <2
1 solutions

Answer 391037 by lwsshak3(6519) About Me  on 2012-06-19 03:21:31 (Show Source):
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|2x+6| <2
solve for two conditions:
2x+6<2
2x<-4
x<-2
and
-2x-6<2
-2x<8
x>-4
..
number line:
<,......(-4<====>-2)............>
solution: (-4,-2)


absolute-value/621875: how would you solve this problem
|6x - 1| - 4 =< 2
1 solutions

Answer 391036 by lwsshak3(6519) About Me  on 2012-06-19 03:11:09 (Show Source):
You can put this solution on YOUR website!
how would you solve this problem
|6x - 1| - 4 =< 2
solve for two conditions: (6x-1) and -(6x-1)
(6x - 1) - 4 ≤ 2
6x - 1 - 4≤ 2
6x ≤ 7
x≤7/6
..
and
-(6x - 1) - 4 ≤ 2
-6x +1 - 4 ≤ 2
-6x ≤ 5
x≥-5/6
..
number line:
<.........[-5/6<====>7/6]............>
solution: [-5/6,7/6]