Answer:
1/sqrt10
Step-by-step explanation:
1) Find out cosA using formula (cosA)^2+(sinA)^2=1
The module of cosA= sqrt (1- (-3/5)^2)= sqrt 16/25=4/5
So cosA=-4/5 or cosA=4/5.
Due to the condition 270degrees< A<360 degrees, 0<cosA<1 that's why cosA=4/5.
2) Find sinA/2 using a formula cosA= 1-2sinA/2*sinA/2 where cosA=4/5.
(sinA/2)^2= 0.1
sinA= sqrt 0.1= 1/ sqrt10 or sinA= - sqrt 0.1= -1/sqrt10
But 270°< A< 360°, then 270/2°<A/2<360/2°
135°<A/2<180°, so sinA/2 must be positive and the only correct answer is
sin A/2= 1/sqrt10
Im assuming you are supposed to factor this problem considering there is no = sign. starting with numbers, you can factor, or divide, both of those numbers by 9. moving on to letters, both terms have a “y” attached to them, so you can take out a y as well. leaving you with the simplified equation being
9y (2x-3)
Answer:

Step-by-step explanation:
![\sf = 13 \% \ of \ 645.2\\\\= \frac{13}{100 } * 645.2\\\\= \frac{13*645.2}{100} \\\\= 8387.6 / 100\\\\= 83.876\\\\\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Csf%20%3D%2013%20%5C%25%20%5C%20of%20%5C%20645.2%5C%5C%5C%5C%3D%20%5Cfrac%7B13%7D%7B100%20%7D%20%2A%20645.2%5C%5C%5C%5C%3D%20%5Cfrac%7B13%2A645.2%7D%7B100%7D%20%5C%5C%5C%5C%3D%208387.6%20%2F%20100%5C%5C%5C%5C%3D%2083.876%5C%5C%5C%5C%5Crule%5B225%5D%7B225%7D%7B2%7D)
Hope this helped!
<h3>~AH1807</h3>