This is a problem of
fact families, but <em>what is fact families?</em> Well it is a family of four things. Two of them are additions and two of them are subtractions. So this question asks about fact families by w<span>riting the <em>subtraction fact two ways</em>. So we have:
</span><span>

First way. So let's take the number 10 and explain this problem using triangles. Let's say that we have 10 triangles in the beginning:
</span>Δ Δ Δ Δ Δ
Δ Δ Δ Δ Δ
So I want to take away 3 triangles, then by taking away 3<em> what is left? </em>Well the answer is 7:
Δ Δ Δ Δ Δ
Δ Δ
That is, if we subtract 3 from 10 then the result is:
Second way. In this subtraction we take the same 10 triangles:
Δ Δ Δ Δ Δ
Δ Δ Δ Δ Δ
Now I want to take away 7 triangles, then by taking away 7 what is left is 3:
Δ Δ Δ
That is, if we subtract 7 from 10 then the result is:
Answer:
dV/dt = 155.74 ft^3/minute
Step-by-step explanation:
Volume V = Area × thickness
Area A= πr ^2
Thickness = 0.2 ft
Volume V = 0.2A = 0.2πr^2
V = 0.2πr^2
Differentiating both sides;
dV/dt = 0.2π × 2r dr/dt = 0.4πr.dr/dt
Given;
r = 400 ft
dr/dt = 0.31 ft/minute
π = 3.14
Substituting the values
dV/dt = 0.4πr.dr/dt = 0.4 × 3.14 × 400 × 0.31
dV/dt = 155.74 ft^3/minute
5 1/2%=5.5%
5.5%=5.5/100=55/1000
55/1000=11/200
Answer:
592,000
Step-by-step explanation:
The new dimensions are 500, 280, and 200. Multiply 2(500*280 + 500*200 + 280*200) to get the answer