If is the water level after days, then at the start we have . After the first day , the water level falls by 1.5, so that . After the second day , the water level falls by a total of 2(1.5) = 3, so that . And so on.
The idea is that has the closed form (to answer part b).
could be any non-negative number of days, which means we can pick from the set of non-negative real numbers. However, after a certain point, our function will start returning negative values, which would translate to the water level falling below the riverbed. So for the purposes of this problem, we should first find out when reaches 0:
That is, the river dries up completely after 14 days. So we can say the domain of is .
The range is the set of values that can take on for the values of in the domain. In this case, we start at 21 and steadily fall to 0, so the range is .
After 9 days, the water level falls to
so in total, the water level would have subsided by a depth of 21 - 7.5 = 13.5 ft.
keep dividing by the prime numbers is ascending order 2, 3 5 ....... ( if they are factors) , of course) until you end up with a prime number:-
80 / 2 = 40
40 / 2 = 20
20 / 2 = 10
10 / 2 = 5
So 80 = 2*2*2*2*5
<h3>Given</h3>
regular paper costs $3.79 per ream
recycled paper costs $5.49 per ream
$582.44 was spent for 116 reams
<h3>Find</h3>
the numbers of reams of each type that were purchased
<h3>Solution</h3>
Let r and g represent the numbers of reams of regular and recycled ("green") paper, respectively.
... r + g = 116 . . . . . . . . 116 reams were purchased
... 3.79r + 5.49g = 582.44 . . . . this is the total cost of the purchase
Solve the first equation for r and substitute that into the second equation.
... r = 116 - g
... 3.79(116 - g) + 5.49g = 582.44 . . . . . use the expression for r
... 1.70g + 439.64 = 582.44 . . . . . . . . . simplify
... g = (582.44 -439.64)/1.70 = 84 . . . . subtract the constant, divide by 1.70
... r = 116 -84 = 32 . . . . . . . . . . . . . . . . . use the equation for r
32 regular reams and 84 recycled reams were purchased
Answer:
0.37
Step-by-step explanation:
Since PQ // BC, ABC and APQ are similar triangles, so we can use the Thales theorem
AB / AP = AC / x it means 9/3 = x + 20/ x because AB=6+3=9
3= x+20) /x implies 3x = x +20, and 2x = 20, finally x= 20/2=10
x= 10