You would have to do distribution. So you would have to multiply 3 by 2a and multiply 3 by -8b. 3 times 2a equals 6a (always keep the letter) and 3 times -8b equals -24b. (if there is only one negative number when multiplying, always keep the negative sign.) now you are left with 6a-24b. and since we cant put a into b, your answer would be 6a-24b. hopefully this helped you and sorry if it confused you
Option B.
5x−2)(4x^2−3x−2)
=(5x+−2)(4x^2+−3x+−2)
=(5x)(4x^2)+(5x)(−3x)+(5x)(−2)+(−2)(4x^2)+(−2)(−3x)+(−2)(−2)
=20x^3−15x^2−10x−8x^2+6x+4
=20x^3−23x^2−4x+4
Saying arccos(-√2/2) is the same as saying cos(x)=-√2/2. This is one the trigonometric values you should have memorized if you are taking a a trig class. In order to get √2/2, x must be equal to 45° or pi/4. But since it is a negative √2/2, the answer would be -45°or -pi/4.
There are technically multiple answers to this, but since you weren't given a range for the answers, I would stick with -45°.
Hope this helps
Option A
The centripetal acceleration is 1.32 
<em><u>Solution:</u></em>
From given question,
A cyclist rides in a circle with speed 5 m/s
The circle has a radius of 19 m
To find: Centripetal acceleration
<em><u>The formula for Centripetal acceleration is given as:</u></em>
Where,
= centripetal acceleration
r is the radius and v is the velocity
From given statement,
radius = r = 19 m
velocity = v = 5 m/s
<em><u>Substituting the values in above formula, we get</u></em>
Thus centripetal acceleration is 1.32
You can subtract 22 inches.
