15) factor out cos: cos(x)(sin(x)+1)=0
Now this is true when either cos(x)=0 (x=pi/2 and 3pi/2)
Or when sin(x)=-1 (x=3pi/2)
So it's solutions are pi/2 and 3pi/2
The answer is a the answer is a
-3x - 18 = 0
-3x = 18
x = -6
Are the cupcakes 37 dollars each or is it 37 dollars for 20 cupcakes?
if they are $37 each then sally can buy 2 cupcakes
if they are $37 for 20 then sally can buy 40 cupcakes