By substitution
f(6) = 1.8×2^(6)
= 1.8×64
= 115.2
Answer:
x = 2.4
Step-by-step explanation:
Simplify.
24 - 4x + 4 = 6x + 2 - 6
Combine like terms (24 + 4 = 28, sorry for the confusion!)
28 - 4x = 6x - 4
Add x and add 4 to both sides.
10x = 32
x = 3.2
Answer:
C
Step-by-step explanation:
Let x = number of pages holding 2 cards,
y = number of pages holding 3 cards.
So his total number of card would be 2x + 3y, which is given as 18. So we get this equation.
2x + 3y = 18
Subtract 3y from both sides:
2x = 18 – 3y
Divide both sides by 2:
x = (18 – 3y)/2
x must be an integer. So 18–3y must be a multiple of 2. Since 18 is a multiple of 2, 3y is also a multiple of 2. Then y must be a multiple of 2 too.
Let's start with y = 0.
When y = 0, x = (18 – 3(0))/2 = 9.
When y = 2, x = (18 – 3(2))/2 = 6.
When y = 4, x = (18 – 3(4))/2 = 3.
When y = 6, x = (18 – 3(6))/2 = 0.
Thus there are 4 ways to display his figures.
Right side of the equation:
cos ( A - B ) - cos ( A + B ) =
= cos A cos B + sin A sin B - ( cos A cos B - sin A sin B ) =
= cos A cos B + sin A sin B - cos A cos B + sin A sin B =
= 2 sin A sin B - left side of the equation ( correct )
