List all the multiples of the numbers:
2: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100
5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100
6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96
9: 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99
The least common multiple of 2, 5, 6, and 9 is 90.
The reciprocal function referred here is the inverse trigonometric function identities. The inverse or reciprocal function of sec x is 1/cos x. Replacing secant with cosine, the equation becomes:
y = (2/cos x) - 3
To graph this, assign random values of x, then you'll get corresponding values of y. Plot the points and connect them together. The graph is shown in the attached picture.
We need to find 30% of 20 gallons.
1) We can write a proportion
20 gallons ---- 100%
x gallons --------30%
x = 20*30/100 = 6 gallons
2) Or we can write 30% as decimal.
30% = 30/100 = 0.3
0.3 of 20 = 0.3*20 =6 gallons
Answer 6 gallons are used efficiently.