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Recent problems solved by 'checkley77'

checkley77 answered: 12560 problems
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Graphs/168541: solve each system by grapting 1. 4y=x+2 2x+y=5 1 solutions Answer 124227 by checkley77(12569)   on 2008-11-19 17:14:06 (Show Source): You can put this solution on YOUR website! 4y=x+2 y=x/4+2/4 y=x/4+.5 (red line) 2x+y=5 y=2y-5 (green line). (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions x/4 +.5 and 2y -5).

Miscellaneous_Word_Problems/168386: Please help me solve this problem: A rectangular pond measures 3m by 5m. A concrete walk of uniform width is constructed around the pond. If the walk and pond together cover an area of 39m^2, how wide is the walk? 1 solutions Answer 124117 by checkley77(12569)   on 2008-11-18 19:45:37 (Show Source): You can put this solution on YOUR website! 3*5=15 M^2 FOR THE POND. (3+2X)(5+2X)=39 15+10X+6X+4X^2-39=0 4X^2+16X-24=0 4(X^2+4X-6)=0 USING THE QUADRATIC EQUATIONWE GET: X=(-4+-SQRT[4^2-4*1*-6])/2*1 X=(-4+-SQRT16+24])/2 X=(-4+-SQRT40)/2 X=(-4+-6.325)/2 X=(-4+6.32)/2 X=2.32/2 X=1.16 M. IS THE WIDTH OF THE WALK. PROOF: (3+2*1.16)(5+2*1.16)=39 (3*2.32)(5+2.32)=39 5.32*7.32=39 39~39

Numbers_Word_Problems/168390: Find four consecutive even integers such that four times the fourth decreased by one half the second is 9. 1 solutions Answer 124115 by checkley77(12569)   on 2008-11-18 19:35:23 (Show Source): You can put this solution on YOUR website! LET X, X+2, X+4 & X+6 BE THE FOUR INTEGERS. 4(X+6)-(X+2)/2=9 4X+24-(X+2)/2=9 4X-(X+2)/2=9-24 (2*4X-X-2)/2=-15 8X-X-2=-30 7X=-30+2 7X=-28 X=-28/7 X=-4 ANS FOR THE SMALLEST INTEGER. -4=2=-2 FOR THE NEXT INTEGER. -4=4=0 FOR THE THIRD INTEGER. -4+6=2 FOR THE LARGEST INTEGER. PROOF: 4*2-(-2/2)=9 8-(-1)=9 8+1=9 9=9

Travel_Word_Problems/168359: A metra commuter train leaves Union Station in Chicago at 12 noon. Two hours later, an amtrak train leaves on the same track, traveling at an average speed that is 50 mph faster that the metra train. At 3 pm, the amtrak train is 10 miles behind the commuter train. How fast is each going? And how did i conclude this answer? 1 solutions Answer 124113 by checkley77(12569)   on 2008-11-18 19:26:59 (Show Source): You can put this solution on YOUR website! D=RT FOR THE METRA D=R*3 FOR THE AMTRAX D-10=(R+50)*1 R3=R+50+10 3R-R=60 2R=60 R=60/2 R=30 MPH FOR THE MATRA TRAIN. 30+50=80 MPH FOR THE AMTRAX TRAIN. PROOF: 3*30=30+50+10 90=90

Proportions/168369: This question is from textbook Let y be 10% of a number. What is 50% of the number? Write your answer in terms of y. 1 solutions Answer 124111 by checkley77(12569)   on 2008-11-18 19:04:18 (Show Source): You can put this solution on YOUR website! y=.1n y=.1n/2 ans.

Equations/168370: slove for x :3(x-10)=-x+18 1 solutions Answer 124110 by checkley77(12569)   on 2008-11-18 18:55:17 (Show Source): You can put this solution on YOUR website! 3(x-10)=-x+18 3x-30=-x=18 3x+x=18+30 4x=48 4x=48 x=48/4 x=12 ans. Proof: 3(12-10)=-12+18 3*2=6 6=6

Linear-equations/168383: Two planes started at the same time from tow different airports that are 3,600 kilometers apart and flew toward each other. One plane flew at 792 kilometers per hour, and the other flew at 888 kilometers per hour. In how many hours were the planes still 240 kilomters apart? 1 solutions Answer 124108 by checkley77(12569)   on 2008-11-18 18:52:16 (Show Source): You can put this solution on YOUR website! 792t+888t=3,600-240 1,680t=3,360 t=3,360/1,680 t=2 hours after takeoff they will be 240 miles apart. Proof: 792*2+888*2=3,600-240 1,584+1,776=3,360 3,360=3,360

percentage/168382: the patel manufacturing company allows for a defect rate of 0.9% on it's production line. The defect average for last week was 3 items out of 1,500. What is the difference between the allowed defect rate and the defect average for last week? 1 solutions Answer 124107 by checkley77(12569)   on 2008-11-18 18:47:58 (Show Source): You can put this solution on YOUR website! 3/1500=.002 or .2% is the defect rate. .9-.2=.7% better than the allowable defect rate.

Graphs/168372: How would I find the solution to the system, x+y= -4 3x-y=-4 by graphing? 1 solutions Answer 124105 by checkley77(12569)   on 2008-11-18 18:45:13 (Show Source): You can put this solution on YOUR website! x+y=-4 y=-x-4 (red line) 3x-y=-4 -y=-3x-4 y=3x+4 (green line) (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions -x -4 and 3x +4). Solution (-2,-2)

Miscellaneous_Word_Problems/168379: A rectangle is three times as long as it is wide. If the length and the width are each increased by 4, the area is increased by 176. Find the dimensions of the orginial rectangle. 1 solutions Answer 124103 by checkley77(12569)   on 2008-11-18 18:40:15 (Show Source): You can put this solution on YOUR website! L=3W 3W*W=(L+4)(W+4)-176 3W^2=(3W+4)(W+4)-176 3W^2=3W^2+12W+4W+16-176 0=16W+16-176 16W=-16+176 16W=160 W=160/16 W=10 ANS. FOR THE ORIGINAL WIDTH . L=3*10=30 ANS. FOR THE ORIGINAL LENGTH. PROOF: 10*30=(10+4)(30+4)-176 300=14*34-176 300=476-176 300=300

Miscellaneous_Word_Problems/168375: Please help me solve this problem: A square picture is mounted in a frame 1 cm wide. The area of the picture is 2/3 of the total area. Find the lenght of a side of the picture. thank you 1 solutions Answer 124100 by checkley77(12569)   on 2008-11-18 18:28:16 (Show Source): You can put this solution on YOUR website! x^2=2/3(x+2)^2 x^2=2/3(x^2+4x+4) x^2=(2x^2+8x+8)/3 3x^2=2x^2+8x+8 3x^2-2x^2-8x-8=0 x^2-8x-8=0 using the quadratic eqationwe get: x=(8+-sqrt[-8^2-4*1*-8])/2*1 x=(8+-sqrt[64+32]) /2 x=(8+-sqrt96)/2 x=(8+-9.7979589)/2 x=(8+9.7979589)/2 x=17.7979589/2 x=8.898979 ans. for the length of the side of the picture. Proof: 8.898979^2=2/3(10.898979)^2 79.19182=2/3*118.78774 79.19182=79.19182

Graphs/168373: How would I find the solution to the system, x+y= -4 3x-y=-4 by graphing? 1 solutions Answer 124096 by checkley77(12569)   on 2008-11-18 18:12:27 (Show Source): You can put this solution on YOUR website! x+y=-4 y=-x-4 (red line) 3x-y=-4 -y=-3x-4 y=3x+4 (green line) (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions -x -4 and 3x +4). Solution (-2,-2)

Square-cubic-other-roots/168352: how do you solve a frcation power like 2 to the 1/10 power 1 solutions Answer 124095 by checkley77(12569)   on 2008-11-18 18:08:15 (Show Source): You can put this solution on YOUR website! 2^(1/10) Fractional exponents usethe numerator(1) as a power & the denominator as a root. Thus we have: The 10th root of 2. OR 10\/(2)=1.07177 ans.

Travel_Word_Problems/168250: Two bike trails have a total length of 20 miles. If the product of the length of the trails is 91, find the length of each trail. 1 solutions Answer 124079 by checkley77(12569)   on 2008-11-18 16:19:20 (Show Source): You can put this solution on YOUR website! X+Y=20 OR X=20-Y XY=91 (20-Y)Y=91 20Y-Y^2-91=0 Y^2-20Y+91=0 (Y-13)(Y-7)=0 Y-13=0 Y=13 ANS. Y-7=0 Y=7 ANS. PROOF: 7*13=91 91=91

Polynomials-and-rational-expressions/168263: Solve using the principle of zero products (x + 1/7)(x - 4/5) = 0 1 solutions Answer 124078 by checkley77(12569)   on 2008-11-18 16:14:55 (Show Source): You can put this solution on YOUR website! (x+1/7)(x-4/5)=0 X^2+X/7-4X/5-4/35=0 X^2+(5X-7*4X)/35-4/35=0 X^2+(5X-28X)/35-4/35=0 X^2-23X/35-4/35=0 ans.

Numbers_Word_Problems/168275: if 1+3+5+7+9+11+13+15+17+19=100 which are five digits(among these) whose total is 50? 1 solutions Answer 124075 by checkley77(12569)   on 2008-11-18 16:09:40 (Show Source): You can put this solution on YOUR website! 1+3+5+7+9+11+13+15+17+19=100 19+11+15+5=50 ANS.

Linear_Equations_And_Systems_Word_Problems/168295: The width of a rectangle is 12 units less than the length. The perimeter is 108 units. Find the length. 1 solutions Answer 124073 by checkley77(12569)   on 2008-11-18 16:05:33 (Show Source): You can put this solution on YOUR website! W=L-12 2W+2L=108 2(L-12)+2L=108 2L-24+2L=108 4L=108+24 4L=132 L=132/4 L=33 IS THE LENGTH. W=33-12 W=21 IS THE LENGTH. pROOF: 2*21+2*33=108 42+66=108 108=108

Linear-equations/168123: the sum of four consecutive even integers is -36 find the number. 1 solutions Answer 123994 by checkley77(12569)   on 2008-11-17 22:19:53 (Show Source): You can put this solution on YOUR website! Let x, x+2, x+4 & x+6 be the 4 integers. x+x+2+x+4+x+6=-36 4x+12=-36 4x=-36-12 4x=-48 x=-12 ans for the smallest integer. -12+2=-10 for the next integer. -12+4=-8 for the next integer. -12+6=-6 for the last integer. Proof: -12-10-8-6=-36 -36=-36

Equations/168131: what is tha answer to 21=x+9 1 solutions Answer 123993 by checkley77(12569)   on 2008-11-17 22:15:43 (Show Source): You can put this solution on YOUR website! 21=x+9 x=21-9 x=12 ans.

Equations/168132: what is tha answer to 21=x+9 1 solutions Answer 123992 by checkley77(12569)   on 2008-11-17 22:14:41 (Show Source): You can put this solution on YOUR website! 21=x+9 x=21-9 x=12 ans.

Miscellaneous_Word_Problems/168171: Apply scientific notation to scientific models/ word problems. 1. Suppose the number of people who live in St. Jerome and pay a water bill is 1,430,000. If the average water bill per month is $80, what is the total amount of money received by the city for water yearly? (Write answer in scientific notation form.) 1 solutions Answer 123991 by checkley77(12569)   on 2008-11-17 22:12:53 (Show Source): You can put this solution on YOUR website! 1,430,000*80=1.144*10^8 ans.

Equations/168189: P+7/2=-5/4 1 solutions Answer 123990 by checkley77(12569)   on 2008-11-17 22:09:52 (Show Source): You can put this solution on YOUR website! P+7/2=-5/4 P=-5/4-7/2 [find a common denominator which is 4) P=(-5-7*2)/4 P=(-5-14)/4 P=-19/4 ANS. ----------------------------- Proof: -19/4+7/2=-5/4 -19/4++14/4=-5/4 -5/4=-5/4 ------------------------------- Thank you checkley77. I really appreciate the break down that you gave me. I just have one concern. If the answer is -19/4 and you put that into the equation as -19/4+7/2 wouldn't that equal -12/6? I am still a little confused. The answer I got for P was -12/2 but I wasn't sure that I had the correct formula. -12/2+7/2=-5/4 -5/2 does not = -5/4 I believe you are confused about the denominators of 2 & 4. In order to combine these fractions they have to have the same denominator. Hpe this helps.

Money_Word_Problems/168192: rick has 20 coins either quarters or nickels if the value of his coins is 2.60 how many nickles does he have 1 solutions Answer 123989 by checkley77(12569)   on 2008-11-17 22:07:37 (Show Source): You can put this solution on YOUR website! Q+N=20 OR Q=20-N .25(20-N)+.05N=2.60 5-.25N+.05N=2.60 -.2N=2.60-5 -.2N=-2.40 N=-2.40/-.2 N=12 NICKELS. Q+12=20 Q=20-12 Q=8 QUARTERS. pROOF: .25*8+.05*12=2.60 2+.60=2.60 2.60=2.60

Expressions-with-variables/168194: ok i've tried this many times. every time i check it though, it's not right so i try a different way, but then it's still not right. i've got 2/3 and 3/2 and something else really weird. please help me. the problem is: x-1 over -4 =2/3 1 solutions Answer 123987 by checkley77(12569)   on 2008-11-17 22:02:08 (Show Source): You can put this solution on YOUR website! (x-1)/-4 =2/3 x-1=2/3*-4 x-1=-8/3 x=-8/3+1 x=(-8+3)/3 x=-5/3 ans. Proof: (-5/3-1)/-4=2/3 (-5-3)/3=2/3*-4 -8/3=-8/3

Percentage-and-ratio-word-problems/168201: i would really appreciate help on this problem i have on my homework. The cost to fix your car was $235.75 for labor and $132.12 for parts. your friend however said he can fix your car for a total of $342.25. what is the percent increase or decrease if your friend fixed your car? specify increase or decrease. 1 solutions Answer 123985 by checkley77(12569)   on 2008-11-17 21:58:11 (Show Source): You can put this solution on YOUR website! 235.75+132.12=367.87 (367.87-342.25)/367.87 25.50/367.87=.0693 or 6.93% is the decrease in estimated price from your friend.

Numeric_Fractions/168212: a-10 over 3 = -4. solve for a. 1 solutions Answer 123982 by checkley77(12569)   on 2008-11-17 21:52:15 (Show Source): You can put this solution on YOUR website! a-10 over 3 = -4 (a-10)/3=-4 a-10=3*-4 a-10=-12 a=-12+10 a=-2 ans. OR: a-10/3=-4 a=-4+10/3 a=(-12+10)/3 a=-2/3

Linear-equations/168220: graph: y = -4x +3 1 solutions Answer 123981 by checkley77(12569)   on 2008-11-17 21:48:09 (Show Source): You can put this solution on YOUR website! graph: y = -4x +3 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, -4x +3).

Graphs/168224: how do you graph equations? can i have it step by step. 1 solutions Answer 123978 by checkley77(12569)   on 2008-11-17 21:46:03 (Show Source): You can put this solution on YOUR website! The line equation is: Y=mX+b where X & Y are a set of points, m=the slope of the line & b=the Y intercept. Example: y=2x-6 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, 2x -6). Here we have X & Y points (3,0) & (0,-6).

Polynomials-and-rational-expressions/168066: Simplify the expression (5^8)^2 (Simplify your answer. Type exponential notation with positive exponents 1 solutions Answer 123904 by checkley77(12569)   on 2008-11-17 17:00:30 (Show Source): You can put this solution on YOUR website! (5^8)^2 (390,625)^2 1.525878906*10^11 ans.

Polynomials-and-rational-expressions/168075: Simplify the expression. (5^8)^2 (Simplify your answer. Type exponential notation with positive exponents.) 1 solutions Answer 123902 by checkley77(12569)   on 2008-11-17 16:58:07 (Show Source): You can put this solution on YOUR website! (5^8)^2 (390,625)^2 1.525878906*10^11 ans.

Matrices-and-determiminant/168088: Please help me understand this 2^d(5^f) - 10^d f = 4 and d = 1 1 solutions Answer 123899 by checkley77(12569)   on 2008-11-17 16:55:03 (Show Source): You can put this solution on YOUR website! 2^d(5^f) - 10^d f = 4 and d = 1 2^1(5^4)-10^1 2*625-10 1,250-10 1,240 ans.