Step-by-step explanation:
4 x 3 + 6
12 + 6
= 18
or
4 x (3+6)
4 x 9
= 36
depends whether the 3+6 is in brackets :)
Answer:
Let the current speed be "c";
Then the boat speed in still wate is "5c":
-----------------------
Upstream speed:
distance = 12 miles ; rate = 5c-c = 4c mph ; time = 12/4c = 3/c hrs
---------------------------
Downstream speed:
distance = 12 miles ; rate = 5c+c = 6c mph ; time = 12/6c = 2/c hrs
Step-by-step explanation:
Equation:
time + time = 2 1/2 hrs
3/c + 2/c = 5/2
Multiply thru by 2c to get:
6 + 4 = 5c
c = 2 mph (speed of the current)
5c = 10 mph (speed of the boat in still water)
Step-by-step explanation:
Answer:
Last choice is correct.
Step-by-step explanation:
Given that ∠C=90°, ∠B=30°, c=10
We know that sum of all angles in a triangle is 180 degree.
∠A+∠B+∠C=180°
∠A+∠30°+∠90°=180°
∠A+∠120°=180°
∠A=60°
Now we can use sin or cos whichever applicable to find missing sides
2b=10
b=5
Similarly
a=8.6602
Hence last choice is correct.
Answer:
x = 14.4
Step-by-step explanation:
x is sin(angle 24/30)×24
how do we get the angle at 24/30 ?
by using the extended Pythagoras for baselines opposite other than 90 degrees.
c² = a² + b² - 2ab×cos(angle opposite of c)
in our example the angle 24/30 is opposite of the side 18.
so,
18² = 24² + 30² - 2×24×30×cos(angle 24/30)
324 = 576 + 900 - 1440×cos(angle 24/30)
324 = 1476 - 1440×cos(angle 24/30)
1440×cos(angle 24/30) = 1152
cos(angle 24/30) = 1152/1440 = 576/720 = 288/360 = 144/180 = 72/90 = 36/45 = 12/15 = 4/5
angle 24/30 = 36.9 degrees
x = sin(36.9) × 24 = 14.4
Answer:
Step-by-step explanation:
Combine Like Terms:
Therefore, 
will be your final answer.
