False
I think that’s right because three times 5 is 15 increased by four is 19 not -8 so...
Cos = adjacent / hypotenuse
cos B = 4/5
B = cos^-1 (4/5)
B = 36.869897....
B = 36.87° (nearest hundredth)
Angle B = 36.87°.
So what I did was I wrote down the problem 50 - 10x = 20.
The first step I did was take 50 and subtract it from both sides: 50 - 10x = 20
-50 -50
After that i cross out the so 50's and take 20 and subtract it to 50 which gave me -30. So when you write this down you rewrite it as: -10x = -30
Last step: take the -10 and divide it by both sides the cross out the two -10's cause it's going to be written as -30/-10 which would give you x = 3. So there is your answer, hope this helps. :)
~Shadow
Answer:
a=22.6549
Step-by-step explanation:
Calculated based on 2 given angles and 1 given side.
∠C = 180° - A - B = 0.99484 rad = 57°
a = c·sin(A)/sin(C) = 22.6549
b = c·sin(B)/sin(C) = 12.33874
Average speed = 
Ishan's Speed uphill = 10mph
Time taken = 18 minutes = 18/60 = 3/10 hours
Now distance = rate × time
Distance traveled by Ishaan up hill = 10 × 3/10 = 3 miles
Now returning back home
Distance = 3 miles
Rate = 30 mph
So time taken = distance/ rate = 3/30= 1/10 hours = 1/10 ×60 = 6 minutes.
Now total distance traveled = 3 + 3 = 6 miles
Total time taken = 18 + 6 = 24 minutes = 24/60 = 2/5 hours
Average speed
= 
= 15 mph
Ishaan's average speed for the entire trip from home to the gift store and back is 15mph