Answer:
The answers are in the question.
Step-by-step explanation:
The wording can be off-putting but the answers are mostly there for you. It says that when the wind was at the tail of the plane, the travel was hastened to 5 hours instead of six. Is the rate of speed with the wind in favor of the plane is r+21, then it stands to reason that traveling AGAINST the wind will cause the rate to drop to r-21. Taking the average of the two travel times (5 and 6 hours each), we get 5.5 hours. Since speed is distance divided by time, the speed of the plane in still air will be <em>d</em> / 5.5
Be sure to label the speed as mph.
Answer:
x=4
Step-by-step explanation:
In order to solve for x, we must isolate x on one side of the equation.
x+3x+5=21
First, combine like terms. x and 3x are both terms with variables, and can be combined.
(x+3x) + 5=21
4x + 5=21
5 is being added to 4x. The inverse of addition is subtraction. Subtract 5 from both sides of the equation.
4x+5-5= 21-5
4x= 16
x is being multiplied by 4. The inverse of multiplication is division. Divide both sides by 4.
4x/4=16/4
x= 16/4
x=4
Let's check our solution. Plug 4 in for x and solve.
x+3x+5=21
4+3(4)+5=21
4+12+5=21
16+5=21
21=21
This solution checks out, so we know our answer is correct.
x is equal to 4, x=4.
Answer:x=1
Step-by-step explanation:
y=y
y = -x + 10
y = 7x + 2
-x+10=7x+2
10=8x+2
8=8x
x=1
Answer:
28 inches
Step-by-step explanation:
P = 2 (a + b) = 2 · (6 + 8) = 28
Answer: If the initial term of an arithmetic sequence is a 1 and the common difference of successive members is d, then the nth term of the sequence is given by: a n = a 1 + (n - 1)d The sum of the first n terms S n of an arithmetic sequence is calculated by the following formula: S n = n (a 1 + a n)/2 = n [2a 1 + (n - 1)d]/2
