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checkley71 answered: 8399 problems
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Expressions-with-variables/127078: This question is from textbook You have a total of 25 coins, all nickels and quarters. The total value is $3.85. Write and solve a system of equations to find the number of nickels n and the number of quarters q that you have. 1 solutions Answer 93101 by checkley71(8403)   on 2008-02-15 09:01:23 (Show Source): You can put this solution on YOUR website! Q+N=25 OR Q=25-N .25Q+.05N=3.85 .25(25-N)+.05N=3.85 6.25-.25N+.05N=3.85 -.2N=3.85-6.25 -.2N=-2.4 N=-2.4/.2 N=12 THE NUMBER OF NICKELS. 25-12=13 QUARTERS. PROOF: .25*13+12*.05=3.85 3.25+.6=3.85 3.85=3.85

Miscellaneous_Word_Problems/127081: The sum of two counting numbers is 91. Half of one number equals three times the other number. What are the number? 1 solutions Answer 93100 by checkley71(8403)   on 2008-02-15 08:56:18 (Show Source): You can put this solution on YOUR website! X+Y=91 OR X=91-Y X/2=3Y (91-Y)/2=3Y NOW CROSS MULTIPLY 6Y=91-Y 7Y=91 Y=91/7 Y=13 ANSWER. X+13=91 X=91-13 X=78 ANSWER. PROOF: 78/2=3*13 39=39

Miscellaneous_Word_Problems/127084: You need 17 lb of fertilizer. The local home and garden store currently has a sale on 'Gro-more' fertilizer. The store offers two sizes: 3 lb for $2.29 and 5 lb for $3.25. What do you buy to obtain at 'least' that amount at the 'lowest cost?' 1 solutions Answer 93099 by checkley71(8403)   on 2008-02-15 08:48:47 (Show Source): You can put this solution on YOUR website! 17/3=5.6 OR 6 BAGS WILL BE NNEDED @2.29*6=$13.74. 17/5=3.4 0R 4 BAGS WILL BE NEEDED @3.25*4=$13. wHICH IS THE BETTER BUY.

Equations/127045: The demand and supply equations for a certain item are given by D = –5p + 40 S = –p^2 + 30p – 8 Find the equilibrium price 1 solutions Answer 93065 by checkley71(8403)   on 2008-02-14 21:03:55 (Show Source): You can put this solution on YOUR website! -5P+40=-p^2+30p-8 p^2-5p-30p+8+40=0 p^2-35p+48=0 p=(35+-sqrt[-35^2-4*1*48])/2*1 p=(35+-sqt[1225-192])/2 p=(35+-sqrt1033)/2 p=(35+-32.14)/2 p=(35+32.14)/2 p=67.14/2 p=33.57 answer. p=(35-32.14)/2 p=2.86/2 p=1.43 answer.

Quadratic_Equations/127052: I typed my problem incorrectly It is 3x squared +x-5 1 solutions Answer 93063 by checkley71(8403)   on 2008-02-14 20:51:07 (Show Source): You can put this solution on YOUR website! 3x^2+x-5 using the quadratic equation we get: x=(-+-sqrt[1^2-4*3*-5])/2*3 x=(-1+-sqr[1+60])/6 x=(-1+-sqrt61)/6 x=(-1+-7.81)/6 x=(-1+7.81)/6 x=6.81/6 x=1.135 answer. x=(-1-7.81)/6 x=-8.81/6 x=-1.468 answer.

Graphs/127046: Janet invested $31,000, part at 10% and part at 1%. If the total interest at the end of the year is $1,390, how much did she invest at 10%? please help 1 solutions Answer 93062 by checkley71(8403)   on 2008-02-14 20:42:50 (Show Source): You can put this solution on YOUR website! .10x+.01(31,000-x)=1390 .10x+310-.01x=1390 .09x=1390-310 .09x=1080 x=1080/.09 x=12,000 answer for the amount invested @ 10%. 31,000-12,000=19,000 amount invested @ 1%. PROOF: .10*12000+.01*19000=1390 1200+190=1390 1390=1390

Expressions-with-variables/126951: This question is from textbook Structure and Method Book 1 3x+2y=26 1 solutions Answer 93060 by checkley71(8403)   on 2008-02-14 20:36:01 (Show Source): You can put this solution on YOUR website! I'll assume this is a line equation. 3x+2y=26 2y=-3x+26 y=-3x/2+26/2 y=-3x/2+13 answer for the standard line equation. (graph 300x200 pixels, x from -6 to 15, y from -10 to 15, -3x/2 +13).

Word_Problems_With_Coins/126959: Mary has 84 coins that have a total value of 5.55$. if all the coins are nickels and dimes. How many of each does mary have? 1 solutions Answer 93054 by checkley71(8403)   on 2008-02-14 20:31:41 (Show Source): You can put this solution on YOUR website! D+N=84 OR D=84-N .10D+.05N=5.55 .10(84-N)+.05N=555. 8.4-.10N+.05N=5.55 -.05N=5.55-8.4 -.05N-2.85 N=-2.85/.05 N=57 IS THE NUMBER OF NICLELS. D+57=84 D=84-57 D=27 IS THE NUMBER OF DIMES. proof: .10*27=.05*57=5.55 2.70+2.85=5.55 5.55=5.55

percentage/126961: Jim is able to sell a hand-carved statue for $670 which was a 35% profit over his cost. How much did the statue originally cost him? need some help on this, thanks 1 solutions Answer 93053 by checkley71(8403)   on 2008-02-14 20:25:29 (Show Source): You can put this solution on YOUR website! x+.35x=670 1.35x=670 x=670/1.35 x=$496.30 is the original cost of the statue.

Polynomials-and-rational-expressions/126993: Express as a binomial: 5(x-4)-4(2x-3)= 1 solutions Answer 93052 by checkley71(8403)   on 2008-02-14 20:21:39 (Show Source): You can put this solution on YOUR website! 5(x-4)-4(2x-3)=5x-20-8x+12=-3x-8 answer.

Polynomials-and-rational-expressions/126995: The length of a rectangle measures 2x-3 and the width measures x+8. Express the perimeter of the rectangle as a binominal in terms of x 1 solutions Answer 93051 by checkley71(8403)   on 2008-02-14 20:19:25 (Show Source): You can put this solution on YOUR website! 2(2x-3)+2(x+8)=4x-6+2x+16=6x+10=2(3x+5)

Complex_Numbers/126999: i need help in this equation i guess 2xsqrd-5x+3=0 1 solutions Answer 93050 by checkley71(8403)   on 2008-02-14 20:16:58 (Show Source): You can put this solution on YOUR website! 2x^2-5x+3=0 (2x-3)(x-1)=0 2x-3=0 2x=3 x=3/2 answer. x-1=0 x=1 answer.

expressions/127003: 2x^2=10-x 1 solutions Answer 93049 by checkley71(8403)   on 2008-02-14 20:12:42 (Show Source): You can put this solution on YOUR website! 2x^2=10-x 2x^2+x-10=0 (2x+5)(x-2)=0 2x+5=0 2x=-5 x=-5/2 x=-2.5 answer. x-2=0 x=2 answer.

Miscellaneous_Word_Problems/127037: If there are 20 people in a room, and each person shakes hands with everyone exactly once, how many handshakes will there be? Thanks for the help. 1 solutions Answer 93048 by checkley71(8403)   on 2008-02-14 20:09:50 (Show Source): You can put this solution on YOUR website! 19+18+17+16+15+14+13+12+11+10+9+8+7+6+5+4+3+2+1=190 hand shakes.

Graphs/127007: graph y=-2(x+1)^2+5 1 solutions Answer 93046 by checkley71(8403)   on 2008-02-14 20:00:15 (Show Source): You can put this solution on YOUR website! Y=-2(X+1)^2+5 Y=-2(X^2+2X-1)+5 Y=-2X^2-4X+2+5 Y=-2X^2-4X+7 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, -2x^2 -4x +7).

Miscellaneous_Word_Problems/127009: a water tank contains 230 L of water when it develops a leak. Water drips out at a rate of 1.5L/min. How long would it take for all the water to drip out? 1 solutions Answer 93042 by checkley71(8403)   on 2008-02-14 19:55:40 (Show Source): You can put this solution on YOUR website! 230/1.5=173.33 MINUTES OR 2.889 HOURS WITH BE REQUIRED TO COMPLETELY DRIP OUT THE TANK.

Travel_Word_Problems/127012: Two trains start toward each other at the same time from towns 450 miles apart. One train travels 6 miles per hour faster than the other train. What is the speed of each train if they meet in 5 hours? This is what I tried : r+6*5=450 r*5=450 r= 90 What am I doing wrong? 1 solutions Answer 93041 by checkley71(8403)   on 2008-02-14 19:52:32 (Show Source): You can put this solution on YOUR website! THIS IS HOW YOU DO IT RIGHT!!!! 450=(x+x+6)5 450=(2x+6)5 450=10x+30 10x=450-30 10x=420 x=420/10 x=42 mph. for the slower train. PROOF: 450=(42+42+6)*5 450=90*5 450=450

Inequalities/127028: 8/5-(-9)=7/2-5 1 solutions Answer 93040 by checkley71(8403)   on 2008-02-14 19:46:37 (Show Source): You can put this solution on YOUR website! 8/5-(-9n)=7/2n-5 8/5+9n=7n/2-5 9n-7n/2=-5-8/5 (18n-7n)/2=(-25-8)/5 11n/2=-33/5 now cross multiply 55n=-66 n=-66/55 n=-6/5 answer. PROOF: 8/5-(-9*-6/5)=(7*-6/5)/2-5 8/5-54/5=(-42/5)/2-5 (-46)/5=(-42/5)*1/2-5 -46/5=-42/10-5 -46/5=(-42-50)/10 -46/5=-92/10 -46/5=-46/5

Inequalities/127033: 8/5-(-9n)=7/2n-5 1 solutions Answer 93039 by checkley71(8403)   on 2008-02-14 19:45:19 (Show Source): You can put this solution on YOUR website! 8/5-(-9n)=7/2n-5 8/5+9n=7n/2-5 9n-7n/2=-5-8/5 (18n-7n)/2=(-25-8)/5 11n/2=-33/5 now cross multiply 55n=-66 n=-66/55 n=-6/5 answer. PROOF: 8/5-(-9*-6/5)=(7*-6/5)/2-5 8/5-54/5=(-42/5)/2-5 (-46)/5=(-42/5)*1/2-5 -46/5=-42/10-5 -46/5=(-42-50)/10 -46/5=-92/10 -46/5=-46/5

Inequalities/127032: 8/5-(-9n)=7/2n-5 1 solutions Answer 93037 by checkley71(8403)   on 2008-02-14 19:43:11 (Show Source): You can put this solution on YOUR website! 8/5-(-9n)=7/2n-5 8/5+9n=7n/2-5 9n-7n/2=-5-8/5 (18n-7n)/2=(-25-8)/5 11n/2=-33/5 now cross multiply 55n=-66 n=-66/55 n=-6/5 answer. PROOF: 8/5-(-9*-6/5)=(7*-6/5)/2-5 8/5-54/5=(-42/5)/2-5 (-46)/5=(-42/5)*1/2-5 -46/5=-42/10-5 -46/5=(-42-50)/10 -46/5=-92/10 -46/5=46/5

Inequalities/127029: 8/5-(-9)=7/2-5 1 solutions Answer 93033 by checkley71(8403)   on 2008-02-14 19:31:12 (Show Source): You can put this solution on YOUR website! 8/5-(-9)=7/2-5 8/5+9=3.5-5 1.6+9=-1.5 10.6=-1.5 doesn't compute????????

Inequalities/127017: I'm totally stuck. In your general biology class, your first three test scores are 67, 77, and 84. What is the lowest score you can get on the fourth test to earn a B for the course? Assume each test is of equal weight and a B is any score greater than or equal to 80. Thanks!! 1 solutions Answer 93032 by checkley71(8403)   on 2008-02-14 19:25:43 (Show Source): You can put this solution on YOUR website! (67+77+84+x)/4>=80 (228+x)/4>=80 now cross multiply 228+x>=320 x>=320-288 x>=92 is the minimum score reaured to maintain an average >=80 on these 4 tests. PROOF: (67+77+84+92)/4>=80 320>=320

Graphs/127024: Solve using the multiplacation mathod. -2x<-6 1 solutions Answer 93029 by checkley71(8403)   on 2008-02-14 19:19:53 (Show Source): You can put this solution on YOUR website! -2x<-6 dividing by a negative number changes the < sign to the > sign. x>-6/-2 x>3 answer. PROOF: let x=3.1 -2*3.1<-6 -6.2<-6

Polynomials-and-rational-expressions/127025: The bottom of a 13-foot long ladder is placed 5 feet away from a wall so that the ladder rests against the top. Assuming the wall is perpendicular to the ground, what is the height of the wall? 1 solutions Answer 93027 by checkley71(8403)   on 2008-02-14 19:17:02 (Show Source): You can put this solution on YOUR website! 5^2+x^2=13^2 25+x^2=169 x^2=169-25 x^2=144 x=sqrt144 x=12 answer. PROOF: 5^2+12^2=13^2 25+144=169 169=169

Probability-and-statistics/127022: If Mr. Wee had 13 apples and 15 oranges. He pulls 2 without looking, what is the probability that they will both be apples? 1 solutions Answer 93025 by checkley71(8403)   on 2008-02-14 19:13:56 (Show Source): You can put this solution on YOUR website! 13/28*12/27=156/756=.206 or 20.6% probability that 2 apples are picked.

Miscellaneous_Word_Problems/127019: if the length of a side of a square is increased by 3 centimeters, the perimeter of the new square is 40 centimeters more than twice the length of a side of the original square. find the dimensions of the original square 1 solutions Answer 93024 by checkley71(8403)   on 2008-02-14 19:09:10 (Show Source): You can put this solution on YOUR website! 4(x+3)=2x+40 4x+12=2x+40 4x-2x=40-12 2x=28 x=28/2 x=14 answer for the originmal length of the sides of the square. PROOF: 4(14+3)=2*14+40 4*17=28+40 68=68

Linear-equations/126976: This question is from textbook algebra structure&method book 1 c/2-d/5=-4 and c-d/5=-8 solve by substitution method 1 solutions Answer 92998 by checkley71(8403)   on 2008-02-14 15:51:29 (Show Source): You can put this solution on YOUR website! C-D/5=-8 OR C=D/5-8 OR C=(D-40)/5 [(D-40)/5)]/2-D/5=-4 (D-40)/5*1/2-D/5=-4 (D-40)/10-D/5=-4 (D-10-2D)/10=-4 (-D-10)/10=-4 -D-10=-40 -D=-40+10 -D=-30 D=30 ANSWER. C-(30/5)=-8 C-6=-8 C=-8+6 C=-2 ANSWER. PROOF: -2-30/5=-8 -2-6=-8 -8=-8

Systems-of-equations/126979: the length of a rectangle is 3in. less than twice its width. If the perimeter of the rectangle is 145 in. find the dimension of the rectangle. 1 solutions Answer 92995 by checkley71(8403)   on 2008-02-14 15:32:28 (Show Source): You can put this solution on YOUR website! L=2W-3 2W+2(2W-3)=145 2W+4W-6=145 6W=145+6 6W=151 W=151/6 W=25.167 IN. IS THE WIDTH. 2*25.167-3=47.33 IN. IS THE LENGTH. PROOF: 2*25.167+2*47.33=145 50.33+94.67=145 145=145

Linear-equations/126862: x-3=y 1 solutions Answer 92973 by checkley71(8403)   on 2008-02-14 10:46:32 (Show Source): You can put this solution on YOUR website! x-3=y y=x-3 (graph 300x200 pixels, x from -5 to 5, y from -5 to 5, x -3).

Triangles/126933: what is the law of sines 1 solutions Answer 92971 by checkley71(8403)   on 2008-02-14 10:36:56 (Show Source): You can put this solution on YOUR website! a/sinA=b/sinB=c/sinC

Linear-equations/126934: This question is from textbook Beginning Algebra How do I determine if the following pair of lines ar parallel, perpendicular or neither. How do I solve the eqaution Line 1 with equation x+2y=6 line 2 with eqaution x+3y=9 1 solutions Answer 92970 by checkley71(8403)   on 2008-02-14 10:34:49 (Show Source): You can put this solution on YOUR website! FIRST YOU MUST [PUT THESE EQUATION INTO THE STANDARD LINE EQUATION FORMAT: Y=mX+b X+2Y=6 OR 2Y=-X+6 OR Y=-X/2+6/2 OR Y=-X/2+3 X+3Y=9 OR 3Y=-X+9 OR Y=-X/3+9/3 OR Y=-X/3+3 THESE 2 LINES ARE NEITHER. PROOF: (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions -x/2 +3 and -x/3 +3).