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.
Answer:
(a - b)^2 = 49 - 4b^2 +2ab
Step-by-step explanation:
Given: a^2 + b^2 = 7b (assuming A is really “a”)
b^2 + (2b - a)^2 = 7^2
Find; (a - b)^2
Plan: Use Algebraic Manipulation
Start with b^2 + (2b - a)^2 = 7^2 =>
b^2 + 4b^2 - 4ab + a^2 = 49 by expanding the binomial.
a^2 + b^2 + 4b^2 - 4ab = 49 rearranging terms
a^2 + b^2 -2ab - 2ab + 4b^2 = 49 =>
a^2 - 2ab + b^2 = 49 - 4b^2 +2ab rearranging and subtracting 4b^2 and adding 2ab to both sides of the equation and by factoring a^2 - 2ab + b^2
(a - b)^2 = 49 - 4b^2 +2ab
Double Check: recalculated ✅ ✅
(a - b)^2 = 49 - 4b^2 +2ab
Mn - 4m - 5n + 20
In this, mn and -4m have a common factor; m. So we can take that out to make it:
m(n-4) -5n + 20
Now, -5n + 20 also has a common factor which is 5, because 20/5 gives you 4, and 5/5 equals 1. So we can talk out that -5 (it doesn't need to be negative, but negatives on variable, no gusta). So you'd get
m(n-4)-5(n-4) OR m(n-4)+5(-n+4)