Math homework help? must be really easy i just dont get it!?

Question

1. When you use 0.5 liters of oil an hour, it will last you a day (24 hours). If you use this oil, x liters an hour, it will last for y hours.
a) make an equation for this problem.
b) if you use this oil 0.3 liters every hour, how many hours will it last?

2. Make an equation for each of these problems.
a) When you walk x km an hour to a destination that is 20 km away, it will take y hours.
b) one side of a right square is 4cm. The area of the right square is equal to the area of a certain parallelogram. The base of the parallelogram is x, and the height is y.

xy= 4x^2 in y=a/x form is what?

Answer 1

Qns 1:

1 hr - 0.5 lit
thus, in 24 hrs, the total volume of oil used is,
24 * 0.5 lit = 12 litres.

(a) therefore,
x hours * y litres = 12 litres
y = 12 / x

(b)
if x is 0.3 lit, then
y = 12 / 0.3
y = 40 hrs.
Using 0.3 litres per hours, the oil will last for 40 hours.

Qns 2:
(a) y = 20 / x
(b)
Area of square = l*b = 4*4 = 16 sq.cm
Area of parallelogram = b*h = x*y sq.cm
since area of square is equal to area of parallelogram,
then xy = 16 sq.cm,
x = 16 /y

Answer 2

It's algebra...

For your first question:
Let's put them into more understandable terms, instead of the generic x and y.
Let's say the amount of oil you have is o(for oil). If you use v litres (v for volume), then it will last you d days.

So the equation here is o = dv.

In this case, o = 12 L.

Now, if we use this oil at a rate of 0.3L/hr, then the equation becomes 12L = d * 0.3L. The answer is then 40 hours, or 1 2/3 days.

Now, your second question...
Once again, get rid of the generic variables.

If you walk s km/h to a destination d km away, it will take t hours.
This is the speed-distance-time ratio, d = st. since d is already given to us, we can change it to 20 = st.

One side of a right square is L cm. The area of the square, a, is equal to the area of a parallelogram. The base of the parallelogram is b, the height h.
Since L is already given to us (4), a therefore equals 16 cm². Now, since the parallelogram has the same area, the equation is 16 = bh. Otherwise it would be L²=a=bh.

Answer 3

for the first question: you have:
0.5L/1 hr = X/24hrs
therefore the total amount of oil that you have is 12 liters. Now as for the equation: X liters/ 1 hr = 12 liters (that is the total)/ Y hrs
thus, the equation is: XY=12, or, Y=12/X

(b) 0.3liters/1 hr = 12 liters/ X hrs
0.3X= 12
X=40 hrs.

2) X km/ 1 hr= 20 km/ Y hrs
XY = 20
Y= 20/X
and that is your equation for the first part.

(b) The area of a parallelogram can be calculated by multiplying its height and base together, and you are told that a square has a side that equals 4 cm. Now the sides of a square are all equal to one another, and that the area of the square and that of the parallelogram are equal to one another. Therefore, the area of the square is: 4 * 4= 16 cm2, and the area of the parallelogram is X*Y, and that is also equal to 16 cm2.
In toher words: XY=16
and, Y= 16/X
I hope this helped you. Good Luck.

Answer 4

1. volumetric rate of consumption = volume / time
from the initial statement,
0.5 l/hr = x / 24 hr
we conclude you have 12 liters

a) x l/hr = 12 l / y
b) 0.3 l/hr = 12 l / y, y = 12 l / 0.3 l/hr = 40 hr

2.
a)speed = distance / time
x km/hr = 20 km / y
b) area of square = length of any side squared
area of parallelogram = base times height
you are told area of parallelogram is same as that of the square, hence:
xy=(4 cm)^2 = 16 cm^2

Answer 5

1. You have 12 liters of this oil

a.) 12/x = y
b.) 40 hours

2. a.)20/x = y

b.) A square would have an area of 16cm^2 so the equation would be: xy = 16cm^2

Answer 6

1 a) 24hrs*(0.5liters/1hr.)=12 liters

well for x liters you get
x liters * (1hr./0.5liters)=y hrs.

1 b) x hrs*(0.3 liters/ 1hr.)= y liters,

2 a) 20km*(1hr./ x km) = y hrs.

2 b) Well for a square the area is b*h. the interesting thing is that if you slice the square into a perfect parallelogram in essence it is two perfect triangles since the base and height is the same.

b*h (area of square)= 2(1/2)*x*y (area of parallelogram)

Answer 7

p.c. is a fraction of one hundred. it somewhat is written with a decimal as .xx because of the fact the 2d place previous the decimal is the hundredths place. So 40 4% = .40 4 or 32% = .32 Now all you gotta do is a few multiplication to make your ideas up maximum of this. For #one million you may remedy the equation as 50 * .35 = answer. to discover a p.c. you may remedy an equation like this for #2: one million.50 * answer = one million.seventy 5 Divide the two components with the aid of one million.50 and you will have an answer which would be some variety of quantity with a one million.xx. If the respond is one million.80 4 then which would be 80 4%. The one million represents the one hundred% of the unique merchandise and the .xx represents the better p.c.. wish that helps.

Answer 8

1.a total amount of oil you have = xy=12
or y=12/x
1.b 12/0.3 = 40 hours

2.a y=20/x
2.b xy=4^2

Answer 9

1a.rate =volume/time,0.5l/h=volume/24h
volume=0.5x24=12liter
rate =volume/time=x=12/y
xy=12
b.40hours
2a.speed =distance/time,x=20/y
area of square=length sqaure =4x4=16cm square
area of parallelogram = length x height=xy
since they are equal, therefore
xy=16

Answer 10

.5 liters/hour * 24 hours = 12 liters
x liters/hour * y hours = x*y liters
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