One way it's useful is in the application of phasors in physics. Phasors require you to add up vectors of two different angles, so the cosine angle addition formula can be used if you already know the cosine and sine of the original vector angles.
Answer:
7/15 for dime
6/15 for pennies
Step-by-step explanation:
7/15 because 7+2+6=15 and there are 7 dimes so 7/15.
6/15 because there are 15 coins and there are 6 pennies so 6/15.
15 is the total so 7 and 6 have to go over it.
Answer is 15%
You have to do a proportion
12. = x
80 100 and u have to cross multiply
80x = 1200
80. 80
then divide 1200÷80=15