I Need Help With Algebra?
Byi need help setting these up….ive asked everyone and almost nobody knows how….the teacher’s always busy
1.) the sides of a triangle can be represented by three consecutive even numbers. if the first side is increased by 1 and the second side is decreased by 1, the triangle becomes isosceles and has a perimeter of 30 in. find the length of each side of the original triangle.
2.) mark is 10 years younger than larry. larry’s age in 8 years will exceed twice marks age 3 years ago by 4 years. how old is each now.
3.) mr. west drove his car from home to chicago at the rate of 40 mph. and returned at a rate of 45 mph. if his time going exceeded his time returning by 30 minutes, find his time going and his time returning.
4.) tom, dick, and harry weigh 50, 85, and 120 pounds. respectively and use a 12 foot plank for a teeterboard. tom sits 5 feet, dick sits 4 feet, and harry sits 3 feet from the fulcrum on the same side. how far must a 200 pound friend sit from the fulcrum to balance them?
5.) find 4 consecutive even integers such that the sum of the third and fourth exceeds 1/3 of the first by the sum of the first and third.
6.) a sum of $3,500 is invested in two parts. one part brings a return of 5% and the other a return of 8%. the total annual return is $250. find the amount invested at each rate.
7.) how many pounds of seed worth 60 cents a pound must be mixed with 300 pounds of seed worth 35 cents a pound to produce a mixture worth 50 cents per pound?
3 Comments
February 27th, 2010 at 7:39 am
Note: I will help, but you have too many problems in one question. Even half of these would be a bit much.
1.) the sides of a triangle can be represented by three consecutive even numbers. if the first side is increased by 1 and the second side is decreased by 1, the triangle becomes isosceles and has a perimeter of 30 in. find the length of each side of the original triangle.
Let x = 1st side
x + 2 = 2nd side
x + 4 = 3rd side
Can you take if from there?
2.) mark is 10 years younger than larry. larry’s age in 8 years will exceed twice marks age 3 years ago by 4 years. how old is each now.
Let x = Larry’s age now
x – 10 = Mark’s age now
x + 8 = Larry’s age in 8 yrs
(x – 10) – 3 = Mark’s age 3 yrs ago
x + 8 = 2[(x - 10) - 3] + 4
3.) mr. west drove his car from home to chicago at the rate of 40 mph. and returned at a rate of 45 mph. if his time going exceeded his time returning by 30 minutes, find his time going and his time returning.
d = r x t
Distance is the same both ways, so r(going) x t(going) = r(returning) x t(returning).
Let t = time returning
t + 30 = time going
r(going) = 40 mph
r(returning) = 45 mph
40(t + 30) = 45t
4.) tom, dick, and harry weigh 50, 85, and 120 pounds. respectively and use a 12 foot plank for a teeterboard. tom sits 5 feet, dick sits 4 feet, and harry sits 3 feet from the fulcrum on the same side. how far must a 200 pound friend sit from the fulcrum to balance them?
I’m assuming the fulcrum is in the center.
x = distance from fulcrum of the 200-lb friend
50(5) + 85(4) + 120(3) = 200x
I think. Haven’t done this in awhile.
5.) find 4 consecutive even integers such that the sum of the third and fourth exceeds 1/3 of the first by the sum of the first and third.
Let x = 1st integer
x + 2 = 2nd integer; x + 4 = 3rd integer; x + 6 = 4th integer.
(x + 4) + (x + 6) = 1/3(x) + x + (x + 4)
6.) a sum of $3,500 is invested in two parts. one part brings a return of 5% and the other a return of 8%. the total annual return is $250. find the amount invested at each rate.
P = principle of 1st part
3500 – P = principle of 2nd part
(5% of P) + (8% of (3500 – P)) = 250
7.) how many pounds of seed worth 60 cents a pound must be mixed with 300 pounds of seed worth 35 cents a pound to produce a mixture worth 50 cents per pound?
x = lbs seed worth 60 cents/lb
total lb of seed = x + 300
60x + 35(300) = 50(x + 300)
Hope this helps!
d
February 27th, 2010 at 8:45 am
uhh so many questions i’ve read all of them
they aint that hard but im so lazy to do all of them
can u tell me which one u havent done =D
February 27th, 2010 at 2:10 pm
1. Okay letting x be first side, then
you know first side is x, 2nd side is x+2,
and third side is x+4.
So, then you know that
(x+1)+(x+2-1)+(x+4)= 30
2. Let m be marks age and
L be larrys age, then
m=L-10 and
L+8=2(m-3)+4 or
L+8=2(L-10-3)+4.
3 Let t be time returning , so
the time going is t+.5, so
40*(t+.5)=45*t
4. Im not sure about this but I think that
distance the 200 friend is from fulcrum is
((3*120)+(4*85)+ (5*50))/(3*200)
5 Let x be first number then
((x+4)+(x+6))=(x/3)+(x+(x+4))
6.Let x be part return of 5% and
y be return of 8%, then
x+y=3500
.05x+.08y=250
7. Let x be number of pounds, the
60x+(300*35)=(x+300)50