The formula for the area of a trapezium is as follows:
<span>area=<span>12</span>(a+b)h
</span>
Let a be the shorter base. Then a = h + 3.
Let b be the longer base. Then b = h + 7.
Substituting these values for a and b in the general formula gives:
<span>
area = 225 = <span>12</span>(h+3+h+7)h = <span>h^2</span>+5h</span>
So you need to solve the following quadratic:
<span><span>h^2</span>+5h−225=0</span>
Step 1: Use quadratic formula with a=1, b=5, c=-225.
<span>h=<span><span><span>−b</span>±<span>√<span><span>b2</span>−<span><span>4a</span>c</span></span></span></span><span>2a</span></span></span><span>h=<span><span><span>−<span>(5)</span></span>±<span>√<span><span><span>(5)</span>2</span>−<span><span>4<span>(1)</span></span><span>(<span>−225</span>)</span></span></span></span></span><span>2<span>(1)</span></span></span></span><span>h=<span><span><span>−5</span>±<span>√925</span></span>2</span></span><span><span>h=<span><span><span>−5/</span>2</span>+<span><span><span><span>5/2</span><span>√37</span></span><span> or </span></span>h</span></span></span>=<span><span><span>−5/</span>2</span>+<span><span><span>−5/</span>2</span><span>√37
</span></span></span></span>Answer:<span><span>h=<span><span><span>−5/</span>2</span>+<span><span><span><span>52</span><span>√37</span></span><span> or </span></span>h</span></span></span>=<span><span><span>−5/</span>2</span>+<span><span><span>−5/</span>2</span><span>√<span>37</span></span></span></span></span>
Answer:
a) 
b) 6.84 million
c) 2028.52
d) 47 years
Step-by-step explanation:
a)Here we know standard exponential growth rate is
In this put t=0 and a(t)=6.27 million
thus we get a = 6.27 million
now 
this is equal to(in 2012)=
b)Put t = 6
we get
=6.84 million
c) 
take log both sides
we get 16.52 years
d) 
take log both sides we get 47 years to get double the current population.
The answer to the question is c. 70°
P = 390,00 + 4000x
450,000 people - (15years x 4000) = 390k in 2010
15 years is the difference between 2010 and 2025
subtract 60k (that is the 15 years multiplied by 4k) from 450k and you get 390k.
Sorry if my explanations suck, I'm not great at explaining my thought process
Answer:
b
Step-by-step explanation:
b
