Exponential equation is
y=a(b)ˣ
when b>1, it is growth
when 0>b>1, it is decay
so
we want the 2nd number to be more than 1
that would be the 3rd one, y=3(8)ˣ
Answer:

Step-by-step explanation:
Given


Required
The distance between the top and John
The distance is calculated using:

Where
--- the angle between the diagonal line and the vertical line


So, we have:






<em> --- approximated</em>
<span> When area is equal 1120. We can write an equation
(x+4)(-x+64)=1120
-x²-4x+64x+256=1120
-x²+60x+256-1120=0
-x²+60x-864=0
D=b² - 4ac= 3600-4*864=144, √D=12
x= (-b+/-√D)/2a
x=(-60+/-12)/(-2)
x=24, x=36
For x=24
(x+4)=24+4=28
(-x+64)=(-24+64)=40
For x=36
(x+4)=36+4=40
(x-64) =(-36+64)=28
So sides should be 28 and 40 in.
We did not get any extraneous solutions. They could be if we get negative length side, for example. They can come because a quadratic equation can
give positive and negative numbers because a^2 and (-a)^2 give the same positive number.
We chose to solve this equation using formula for quadratic equations, because this equation has too big numbers to solve it using other methods.
</span>
D.
first, eliminate B and C, because the highest degree in these two equation is 3, a 3-degree equation has 3 roots, not 4.
between A and D, A has the roots 0, 0, 7, and -7, all real roots.
D can be factored into (x²-49)(x²+1)=0
x²=49 or x²=-1
x=7 or -7, x=i or -i two real roots, two unreal roots
for the second equation:
first, find the first term by using the formula:
the nth term=the first term + (n-1)*difference
you are given the 13th term and d=3.7
a13=a1+(13-1)d
1.9=a1+12*3.7
a1=-42.5
the sum of the first 13 terms is S=(a1+a13)*(13/2)=(-42.5+1.9)*6.5=-263.9