The square of a binomial expands as follows:

Expanding all the binomials, we have

Sum like terms:

Simplify terms appearing on both sides:

Move all terms involving k to the left and all numbers to the right:

Divide both sides by -20:

2% of 300 would be 6 and 6 rounded to the nearest 100th is 6.00
Speed = dis / time
let plane speed in still air is X and air speed Y
so, X-Y = 2280/4 = 570 km/h
and X+Y = 6650/7 = 950 km/h
so, X = (570 + 950) / 2 = 760 km/h
and Y = 950- 760 = 190 km/h
:)
Answer:
t= 3 years
Step-by-step explanation:
So far we have 2 useful relationships
and 
Now, clearing t

I apply logarithm
years
Done
We know that In right angle triangle c^2 = a^2 + b^2.
19^2 = 3^2 + b^2
b = (361 - 9)^1/2 = 18.761663039294
Now for angles
sin(A) = a/c = 3/19
A = sin{-1}(3/19) = 9.0847202873911
A = 9.0847202873911
sin(B) = b/c = 18.761663039294 / 19
B = sin{-1}(18.761663039294 / 19) = 80.915279712614
B = 80.915279712614