Step one: common denominators ex. 25/100, 79/100
step two: add the numerators and keep the denominators the same (addition)
step three: biggest fraction first!! subtract the numerators keep the denominators the same (subtraction)
step four: have a nice time with fractions
Answer:
the answer is 0, have a nice day
Answer:
81.87°
Step-by-step explanation:
The angle a line makes with the x-axis is equal to the arctangent of its slope. Here, L1 makes an angle of arctan(0.5) = 26.57° with the x-axis; L2 makes an angle of arctan(-3) = -71.57° with the x-axis. The difference between these angles is ...
26.57° -(-71.57°) ≈ 98.13° . . . . . . all numbers rounded to 2 decimal places
This is an obtuse angle, so the acute angle is ...
180° -98.13° = 81.87°
_____
You can also use the trig formula for the difference of angles. Tan(α) is the slope of the first line, 0.5. Tan(β) is the slope of the second line, -3.
tan(α-β) = (tan(α)-tan(β))/(1 +tan(α)tan(β))
tan(angle) = (0.5 -(-3))/(1 +(0.5)(-3)) = 3.5/(-0.5) = -7
angle = arctan(-7) = -81.87°
The angle between the two lines is 81.87°.
We must find UNIQUE combinations because choosing a,b,c,d... is the same as d,c,b,a...etc. For this type of problem you use the "n choose k" formula...
n!/(k!(n-k)!), n=total number of choices available, k=number of choices made..
In this case:
20!/(10!(20-10)!)
20!/(10!*10!)
184756