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Recent problems solved by 'checkley77'

checkley77 answered: 12560 problems
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Money_Word_Problems/250184: a mark up rate of 20% is used on a sweater with a selling price of 2=$24. find the cost of the sweater 1 solutions Answer 182236 by checkley77(12569)   on 2009-12-15 18:09:34 (Show Source): You can put this solution on YOUR website! 2x=24 x=24/2=$12 price of one sweater. z+.20z=12 1.2z=12 z=12/1.2 z=$10 is the original price before the 20% mark up.

Distributive-associative-commutative-properties/250192: Solve by the Elimination Method. 7r - 5s = 11. 5r + 7s = 103. 1 solutions Answer 182232 by checkley77(12569)   on 2009-12-15 18:02:46 (Show Source): You can put this solution on YOUR website! 7r - 5s = 11. multipl by 7 5r + 7s = 103. multiply by 5 & add. 49r-35s=77 25r+35s=515 -------------- 74r=592 r=592/74 r=8 ans. 7*8-5s=11 56-5s=11 -5s=11-56 -5s=-45 s=-45/-5 s=9 ans. Proof: 5*8+7*9=103 40+63=103 103=103

Distributive-associative-commutative-properties/250197: 25% of what number is 20? 1 solutions Answer 182231 by checkley77(12569)   on 2009-12-15 17:57:46 (Show Source): You can put this solution on YOUR website! .25X=20 X=20/.25 X=80 ANS.

Distributive-associative-commutative-properties/250205: Use the intercepts to graph. x + 2y = 4. 1 solutions Answer 182227 by checkley77(12569)   on 2009-12-15 17:54:02 (Show Source): You can put this solution on YOUR website! x+2y=4 SET Y=0 & SOLVE FOR X. X+2*0=4 X=4 (4,0) X INTERCEPT. SET X=0 & SOLVE FOR Y. 0+2Y=4 2Y=4 Y=4/2=2 (0,2) Y INTERCEPT. X+2Y=4 2Y=-X+4 Y=-X/2+4/2 Y=-X/2+2 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, -x/2 +2).

Circles/250206: Find the circumference, to the nearest tenth, of a circle with a diameter of 16 cm. Use 3.14 to approximate π 1 solutions Answer 182225 by checkley77(12569)   on 2009-12-15 17:44:47 (Show Source): You can put this solution on YOUR website! C=2PIR C=2*3.14*16/2 C=2*3.14*8=50.2 ANS.

Linear-equations/250208: Please help me solve this equation: Solve by finding the in slope-intercept form and standard form: Through (2,-5) and (1,4) 1 solutions Answer 182223 by checkley77(12569)   on 2009-12-15 17:42:03 (Show Source): You can put this solution on YOUR website! (2,-5) and (1,4) Y=mX+b m=SLOPE=(Y2-Y10/X2-X1)=(4+5)/(1-2)=9/-1=-9 ANS. FOR THE SLOPE USE ONE SET OF X,Y VALUES & SOLVE FOR b -5=-9*2+b -5=-18+b b=-5+18 b=13 ans. for the Y intercept. Y=-9X+13 (graph 300x200 pixels, x from -6 to 5, y from -10 to 15, -9x +13).

Travel_Word_Problems/250209: How far can a plane travel if it flies at a rate of 190 miles per hour for 5 hours? 1 solutions Answer 182218 by checkley77(12569)   on 2009-12-15 17:36:24 (Show Source): You can put this solution on YOUR website! D=RT D=190*5=950 MILES. ANS.

Word_Problems_With_Coins/250212: what does this mean and how to solve ( he has twice as many quarters as nickel?) 1 solutions Answer 182216 by checkley77(12569)   on 2009-12-15 17:35:16 (Show Source): You can put this solution on YOUR website! 2Q=N INDICATES TWICE AS MANY QUARTERS AS NICKELS.

Mixture_Word_Problems/250213: Please help me solve this problem. How many grams of salt must be added to 40 grams of a 28% salt solution to obtain a 40% salt solution? 1 solutions Answer 182215 by checkley77(12569)   on 2009-12-15 17:33:43 (Show Source): You can put this solution on YOUR website! x+.28*40=.40(40+x) x+11.2=16+.40x x-.40x=16-11.2 .6x=4.8 x=4.8/.6 x=8 grams of salt are used. Proof: 8+.28*40=.40(40+8) 8+11.2=.40*48 19.2=19.2

Linear-equations/250214: Please help me with the problem:write an equation of the line that passes through the points(2,3)and(4,5) 1 solutions Answer 182212 by checkley77(12569)   on 2009-12-15 17:28:41 (Show Source): You can put this solution on YOUR website! (2,3)and(4,5) Slope=(y2-y1)/x2-x1)=(5-3)/(4-2)=2/2=1 3=1*2+b 3=2+b b=3-2 b=1 the y intercept. Y=X+1 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, x +1).

Linear-equations/250247: find an equation of the line containing the given pair of points (3,5) and (9,6) 1 solutions Answer 182209 by checkley77(12569)   on 2009-12-15 17:22:41 (Show Source): You can put this solution on YOUR website! (3,5) and (9,6) Slope=(y2-y1)/(x2-x1)=(6-5)/(9-3)=1/6 ans. Y=mX+b 5=1/6*3+b 5=3/6+b 5-1/3=b b=15/3-1/3 b=14/3 Y intercept. Y=X/6+14/3 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, x/6 +14/3).

Graphs/250265: find the vertex, y intercept and x intercept if any exist of f(x)=-xSQUARED+2x+8 1 solutions Answer 182207 by checkley77(12569)   on 2009-12-15 17:14:20 (Show Source): You can put this solution on YOUR website! f(x)=-x^2+2x+8 (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, -x^2 +2x +8). Vertex=(1,9) Y intercept=8 X intercepts=-2 & 4

Permutations/250270: find the term not involving y in the expansion of { 1/y^3 + y^2)^5 Pls explain- I am super lost my textbooks don't give me any questions like this. 1 solutions Answer 182204 by checkley77(12569)   on 2009-12-15 17:05:58 (Show Source): You can put this solution on YOUR website! { 1/y^3 + y^2)^5 {1/y^15+y^10} You have three terms in this epression 1, y^15 & y^10. The only term not involving y is the [1] in the numerator.

Human-and-algebraic-language/250279: If Sally can paint a house in 4 hours, and John can paint the same house in 6 hour, how long will it take for both of them to paint the house together? 1 solutions Answer 182202 by checkley77(12569)   on 2009-12-15 17:00:33 (Show Source): You can put this solution on YOUR website! 4*6/(4+6)=24/10=2.4 hours working together they'll finish the job.

Systems-of-equations/250271: 2x+3y=7 3x+4y=10 i need to find teh exact point where these two systems fo equations meet. can anybody help me? 1 solutions Answer 182200 by checkley77(12569)   on 2009-12-15 16:57:22 (Show Source): You can put this solution on YOUR website! 2x+3y=7 3y=-2x+7 y=-2x/3+7/3 (red line) ------------------ 3x+4y=10 4y=-3x+10 y=-3x/4+10/4 y=-3x/4+2.5 (green line) ------------------------- (graph 300x200 pixels, x from -6 to 5, y from -6 to 5, of TWO functions -2x/3 +7/3 and -3x/4 +2.5 ). y=-2x/3+7/3 -(y=-3x/4+2.5) subtract --------------------- 0=-2x/3+3x/4+7/3-2.5 0=(-2x*4+3x*3+7*4)/3*4-2.5 0=(-8x+9x+28)/12-2.5 0=(x+28)/12-2.5 (x+28)/12=2.5 x+28=12*2.5 x+28=30 x=30-28 x=2 ans. y=-2*2/3+7/3 y=-4/3+7/3 y=3/3=1 ans. Intercept (2,1)

Linear-equations/250095: Hi can someone help me solve this please? -5<4x-4<-3 the solution is {x/? any help will be appreciated thanks 1 solutions Answer 182065 by checkley77(12569)   on 2009-12-15 08:27:19 (Show Source): You can put this solution on YOUR website! -5<4x-4<-3 -5+4<4x<-3+4 -1<4x<1 -1/4

Radicals/250099: what number can be subtracted from the numerator and denominator of the fraction 14/17 so that the value of the new fraction will 9/11? 1 solutions Answer 182063 by checkley77(12569)   on 2009-12-15 08:24:55 (Show Source): You can put this solution on YOUR website! 14/17-x=9/11 -x=9/11-14/17 -x=(9*17-14*11)/11*17 -x=(102-154)/187 -x=-52/187 -x=-52/187 x=52/187 ans.

Mixture_Word_Problems/249901: how many ounces of 15% salt solution must be added to the 30 ounce of 70% salt solution to produce a 45% salt solution? 1 solutions Answer 182026 by checkley77(12569)   on 2009-12-14 22:30:12 (Show Source): You can put this solution on YOUR website! .30*70+.15x=.45(30+x) 21+.15x=13.5+.45x .15x-.45x=13.5-21 -.3x=-7.5 x=-7.5/-.3 x=25 oz. of 15% salt is used. Proof: .30*70+.15*25=.45(30+25) 21+3.75=.45*55 24.75=24.75

Circles/249904: You have installed a new irragration system. Each irrigation arm covers a circular region with a radius of 35 feet. How many square feet will 4 irrigation arms cover? 1 solutions Answer 182021 by checkley77(12569)   on 2009-12-14 22:25:18 (Show Source): You can put this solution on YOUR website! Area=pir^2=3.14*35^2=3.14*1,225=3,846.5 ft^2 for each sprinkler. 4*3,846.5=15.386 ft^2 is the area covered by 4 sprinkler systems.

Triangles/249912: A right triangle one base is 10 inches the other is 20 inches what is the side of the 3rd triangle 1 solutions Answer 182019 by checkley77(12569)   on 2009-12-14 22:21:47 (Show Source): You can put this solution on YOUR website! If the 20 in. side is not the hypotenuse then: a^2+b^2=c^2 10^2+20^2=c^2 100+400=^2 500=c^2 c=sqrt500 c=22.36 in. ans. for the third side.

Distributive-associative-commutative-properties/249928: Are the lines parallel, perpendicular or neither? 4x + 3y +5 and 3x -4y = 10. 1 solutions Answer 182015 by checkley77(12569)   on 2009-12-14 22:17:41 (Show Source): You can put this solution on YOUR website! 4x + 3y +5 3y=-4x=5 y=-4x/3+5/3 slope=-4/3 (red line) 3x -4y = 10 -4y=-3x+10 y=-3x/-4+10/-4 y=3x/4-2.5 slope=3/4 (green line. Because the slopes are negative recipricals of each other these lines are perpendicular. (graph 200x200 pixels, x from -6 to 5, y from -6 to 5, of TWO functions -4x/3 +5/3 and 3x/4 -2.5).

Linear-systems/249937: Solve system by elimination: 3x-2y=-1 3x-4y=9 1 solutions Answer 182012 by checkley77(12569)   on 2009-12-14 22:11:59 (Show Source): You can put this solution on YOUR website! 3x-2y=-1 -(3x-4y=9) subtract ----------------- 2y=-10 y=-10/2 y=-5 ans. 3x-2*-5=-1 3x+10=-1 3x=-1-10 3x=-11 x=-11/3 ans. Proof: 3*-11/3-4*-5=9 -11+20=9 9=9

Quadratic_Equations/249938: x^2-8x+15=0 how do you solve this problem, and how do you use the discriminant? 1 solutions Answer 182010 by checkley77(12569)   on 2009-12-14 22:07:34 (Show Source): You can put this solution on YOUR website! x^2-8x+15=0 (x-5)(x-3)=0 x-5=0 x=5 ans. x-3=0 x=3 ans. The discriminate is b^2-4ac. -8^2-4*1*15=-64-60=4 Because the answer is a perect square then the answers are 2 real rational numbers.

Distributive-associative-commutative-properties/249939: What is the y-intercept in y + x = 2? 1 solutions Answer 182005 by checkley77(12569)   on 2009-12-14 21:57:13 (Show Source): You can put this solution on YOUR website! y=mx+b where b=the y intercept. y + x = 2 y=-x+2 thus the y intercept=2.

Square-cubic-other-roots/250008: how do you write a square root problem such as the square root of 60 over square root of 50 ? 1 solutions Answer 182003 by checkley77(12569)   on 2009-12-14 21:54:37 (Show Source): You can put this solution on YOUR website! sqrt60/sqrt50 sqrt(4*15)/sqrt(25*2) 2sqrt15/5sqrt2 ans.

Numbers_Word_Problems/249945: the sum of two consecutive even integers is equal to seven times the first decreased by 18. find the integers. 1 solutions Answer 182002 by checkley77(12569)   on 2009-12-14 21:49:56 (Show Source): You can put this solution on YOUR website! Let x & x=2 be the 2 integers. x+x+2=7x-18 2x-7x=-18-2 -5x=-20/-5 x=4 ans. 4+2=6 ans. Proof: 4+6=7*4-18 10=28-18 10=10

Volume/249963: If a cube has a total surface area of 486 square feet, then it is ??? feet on each edge. 1 solutions Answer 181999 by checkley77(12569)   on 2009-12-14 21:44:15 (Show Source): You can put this solution on YOUR website! A square has 6 equal square surfaces. 6x^2=486 x^2=486/6 x^2=81 x=sqrt81 x=9 ft on a side. Proof: 6*9^2=486 6*81=486 486=486

Distributive-associative-commutative-properties/249964: Decide whether the pair of lines is parallel, perpendicular, or neither. 4x + 3y = 5 3x - 4y = 10 1 solutions Answer 181997 by checkley77(12569)   on 2009-12-14 21:40:37 (Show Source): You can put this solution on YOUR website! 4x + 3y = 5 3y=-4x+5 y=-4x/3+5/3 (red line) This line has a slope=-4/3 3x - 4y = 10 -4y=-3x+10 y=-3x/-4+10/-4 y=3x/4-2.5 Green line) This line has a slope=3/4 Thus these 2 lines are perpendicular. (graph 300x300 pixels, x from -6 to 5, y from -6 to 5, of TWO functions -4x/5 +5/3 and 3x/4 -2.5).

Equations/249983: Solve each system by substitution. Check your solution. 19. a-1.2b=-3 0.2b+0.6a=12 1 solutions Answer 181992 by checkley77(12569)   on 2009-12-14 21:33:51 (Show Source): You can put this solution on YOUR website! a-1.2b=-3 or a=1.2b-3 0.2b+0.6a=12 .2b+.6(1.2b-3)=12 .2b+.72b-1.8=12 .92b=12+1.8 .92b=13.8 b=13.8/.92 b=15 ans. a=1.2*15-3 a=18-3 a=15 ans. Proof: .2*15+.6*15=12 3+9=12 12=12

Linear-equations/249985: Media services charges $20 for a phone and $30/month for a plan. The equation c=30t+20 describes the total cost, c of operating the phone and t for the months The total cost of 2 months service is? and if a customer has only $90 available, how many moths service can they receive? Help pleeese? Thanks 1 solutions Answer 181989 by checkley77(12569)   on 2009-12-14 21:32:31 (Show Source): You can put this solution on YOUR website! c=20+30*2=20+60=$80 for 2 months service. 20+30t<90 30t<90-20 30t<70 t=70/30 t=2.333 months can be had for $90.

Linear-systems/249994: Solve each system by substitution. Check your solution. 19. a-1.2b=-3 0.2b+0.6a=12 1 solutions Answer 181980 by checkley77(12569)   on 2009-12-14 21:26:51 (Show Source): You can put this solution on YOUR website! a-1.2b=-3 or a=1.2b-3 0.2b+0.6a=12 .2b+.6(1.2b-3)=12 .2b+.72b-1.8=12 .92b=12+1.8 .92b=13.8 b=13.8/.92 b=15 ans. a=1.2*15-3 a=18-3 a=15 ans. Proof: .2*15+.6*15=12 3+9=12 12=12