Answer:
d.x=-8 and x=-10
Step-by-step explanation:
First i got the area which is : A= a+b divided by 2 x height
=2.5+3.5 divided by 2 x 2= 6
Area = 6
To get the perimeter you just add all the sides together so: 3.5+2.5+2.5+2.5= 11
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form y/x=k or y=kx
so
That means it's the equation of a line passing through the origin.
case a) and case d) are discarded because the line does not pass through the origin
<u>case b) we have</u>
for x=2 y=4
y/x=k-------> 4/2=2------> k=2
y=2x-------> in this case the value of y is two times the value of x
<u>case c) we have</u>
for x=4 y=2
y/x=k-------> 2/4=1/2------> k=(1/2)
y=(1/2)x-------> in this case the value of y is one-half of the value of x
therefore
the solution is the case c) see the attached figure
Answer: Aproximately 2,525 balloons
Step-by-step explanation:
1. Find the volume of a balloon with the formula given in the problem, where
is the radius (
), then:

2. Convert the volume from m³ to lliters by multiplying it by 1,000:

3. You know that that 1 liter of helium can lift 1 gram and that Ryan weighs 5 stone and 5 pounds. So you must make the following conversions:
1 g=0.0022 lb
From 5 stones to pounds

4. Then Ryan's weigh is:
5lb+70lb=75lb
5. Then, if 1 liter of helium can lift 0.0022 lb, to lift 75 lb (which is the weight of Ryan) they need:

6. Then, to calculate the aproximated number of balloons they need to make him float (which can call
), you must divide the liters of helium needed to lift the weight of Ryan by the volume of a balloon, then the result is:

≈2,525 balloons.
The numbers in pie are 3.14159