Answer:
a) 160°
b) 18 sides
Step-by-step explanation:
Interior angle = 180 - exterior
= 180 - 20 = 160°
Each angle of a regular polygon:
[(n-2)×180]/n = 160
180n - 360 = 160n
20n = 360
n = 18
Alternate approach for no. of sides:
360/n = each exterior angle
360/n = 20
n = 360/20 = 18
Answer:
f(x) = x⁴-6x³-13x²+66x+72
Step-by-step explanation:
Factors are: (x+3)(x+1)(x-4)(x-6)
[(x+3)(x+1)][(x-4)(x-6)]
[x²+3x+x+3][x²-4x-6x+24]
(x²+4x+3)(x²-10x+24)
x⁴+4x³+3x²-10x³-40x²-30x+24x²+96x+72
f(x) = x⁴-6x³-13x²+66x+72
The string is assumed to be massless so the tension is the sting above the 12.0 N block has the same magnitude to the horizontal tension pulling to the right of the 20.0 N block. Thus,
1.22 a = 12.0 - T (eqn 1)
and for the 20.0 N block:
2.04 a = T - 20.0 x 0.325 (using µ(k) for the coefficient of friction)
2.04 a = T - 6.5 (eqn 2)
[eqn 1] + [eqn 2] → 3.26 a = 5.5
a = 1.69 m/s²
Subs a = 1.69 into [eqn 2] → 2.04 x 1.69 = T - 6.5
T = 9.95 N
Now want the resultant force acting on the 20.0 N block:
Resultant force acting on the 20.0 N block = 9.95 - 20.0 x 0.325 = 3.45 N
<span>Units have to be consistent ... so have to convert 75.0 cm to m: </span>
75.0 cm = 75.0 cm x [1 m / 100 cm] = 0.750 m
<span>work done on the 20.0 N block = 3.45 x 0.750 = 2.59 J</span>

This is equal to:

When you add a negative number, it turns into subtraction.
First, I would change it to mixed numbers:

Now, you need to change the denominators to make sure they are the same on both fractions. I changed the first fraction's denominator to 4 so they match. You can do this by multiplying the numerator by 2:

Now, you simply subtract:
10-9=1
1/4 is your answer.
I hope this helps :)