Answer:
The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try! A variable doesn't have to be "x", it could be "y", "w" or any letter, name or symbol. See: Variable.
Step-by-step explanation:
-4 and -5
because to get 16 to 12 you have to subtract 4 but it wants you to add so you put a negative sign infront of it.
and a negative multiply by a negative equals a positive so -3×-5=15
Step-by-step explanation:
multiple possibilities.
e.g.
we could use Pythagoras to get QR, and then use the law of sine to get angle P.
or we can use the law of sine to get angle R, and then use the rule that the sum of all angles in a triangle is always 180° to get angle P.
I propose the second option :
the law of sine :
a/sin(A) = b/sin(B) = c/sin(C)
with a, b, c being the sides always opposite of their associated angles.
33.8/sin(R) = 57.6/sin(90) = 57.6
sin(R) = 33.8/57.6 = 0.586805555...
R = 35.93064691...°
180 = 90 + 35.93064691... + P
P = 54.06935309...°
Answer:
Here:
Step-by-step explanation:
Answer:
Morning's average rate = 50 mph, and Afternoon's average rate = 25 mph.
Step-by-step explanation:
Suppose he drove 150 miles for X hours, then his average rate in the morning was (150/X) mph.
Given that he spent 5 hours in driving.
And he drove 50 miles for (5-X) hours, then his average rate in the afternoon was 50/(5-X) mph.
Given that his average rate in the morning was twice his average rate in the afternoon.
(150/x) = 2 * 50/(5-x)
150/x = 100/(5-x)
Cross multiplying terms, we get:-
150*(5-x) = 100*x
750 - 150x = 100x
750 = 100x + 150x
750 = 250x
x = 750/250 = 3.
It means he spent 3 hours in the morning and 2 hours in the afternoon.
So morning's average rate = 150/3 = 50 mph.
and afternoon's average rate = 50/(5-3) = 25 mph.
