Answer:
≈ 7
Step-by-step explanation:
Let the numbers be x and y. Then xy = -30 and x+y = -3.
Solve xy = -30 for y: y = -30/x
subst. -30/x for y in x+y= -3: x - 30/x = -3
Multiply all 3 terms by x: x^2 - 30 = -3x, so x^2 + 3x - 10 = 0
Solve this quadratic equation for x. x: {-5, 2}
If x = -5, then x+y = -3 becomes -5 + y = -3, and y = 2.
You should check to determine whether x=2 is also correct. If it is, what is the corresponding y value?
Answer: 2 11/24
Step-by-step explanation:
How many hours does the plane save?
Time taken for the train = 5 1/8
Time taken for the plane = 2 2/3
The number of hours saved will then be:
= 5 1/8 - 2 2/3
Let the lowest common multiple be 24
= 5 3/24 - 2 16/24
= 2 11/24
The number of hours saved by the plane will be 2 11/24
Answer:

Step-by-step explanation:
We want to solve
, where
.
We rewrite in terms of sine and cosine.


Use the Pythagorean identity:
.




This is a quadratic equation in
.
By the quadratic formula, we have:




or 
or 
or 
When
, 
on the interval
.
When
,
is not defined because 