Answer:
k=2/3
Step-by-step explanation:
Step 1:
Step 1 in solving the exponential equations is re-writing the base same as other side of the equation
so,

Step 2:
Second step is equating the exponents
The rule used is:

So in this case

So the solution is:
k=2/3 ..
9x⁹ - 90x⁸ - 351x⁷
What do each of these numbers have in common?
They ALL have 9x⁷ in them!
So, divide each one of these by 9x⁷
9x⁹ ÷ 9x⁷ = 9x²
-90x⁸ ÷ 9x⁷ = -9x
-351x⁷ ÷ 9x⁷ = -39
So, factorized completely, it is :
9x² - 9x - 39
~Hope I helped!~
0 = -16t²+64t+80
Finding the roots of the equation:
-16(t² - 4t - 5) = 0
-16(t-5)(t+1) = 0
t = 5, t = -1. Time cannot be negative, so after 5 seconds it will hit the ground.