Answer:
see explanation
Step-by-step explanation:
Using the trigonometric identities
secx = , cosecx =
cotx = , tanx =
Consider the left side
secA cosecA - cotA
= ×
-
= -
=
= ( cancel sinA on numerator/ denominator )
=
= tanA = right side ⇒ proven
Melanie: 15 years old
Kevin: 5 years old
Assume Kevin's present age is x.
That means that 3 years ago, his age would be x - 3.
Melanie's age would be 6(x - 3).
Same thing for 5 years into the future:
Kevin's age would be x + 5.
Melanie's age would be 2(x + 5).
The two equations we have here are:
By subtracting both equations, we are simplified to:
8 = -4x + 28
By solving the equation, we get x = 5.
That means that Kevin's current age is 5 years old.
Melanie's age could be calculated by substituting Kevins'.
6(x - 3) --> 6(5 - 3) --> 12
Since that was 3 years ago, you need to add 3 to 12 to get her current age.
12 + 3 = 15
Melanie's current age is 15 years old.
