Answer:
I hope this is helpful wish you the luck
We know, cos A + cos B = 2cos(C+D)/2 × cos(C - D)/2
So,
cos 130 + cos 110 + cos 10
cos 130 + 2cos (110+10)/2 × cos( 110-10)/2
cos 130 + 2cos 60 × cos 50
cos ( 180 - 50 ) + 2cos60 cos 50
We know, cos ( 180 - A ) = -cos A
2cos 60 cos 50 - cos 50
Also, cos 60 = 0.5
2×0.5 cos 50 - cos50
cos 50 - cos 50
0 = RHS.
Hence proved
Revealed means to be shown or uncovered if I read it right
Hello!
Since Linda has 871.43 and the subtract “x” money every month the equation is... 0=871.43-x*y where “x” is the monthly fee and y is the number of months that have passed. If x=9 meaning the monthly fee is 9 dollars a month, then in the equation you put x=9 to get 0=871.43-9y and solve for y, number of months.
9y=871.43
y=96.83 or about 97 months.
I hope I could help! :)
2^-5 simplified in decimal form is 0.03125
5^-3 simplified in decimal form is 0.008
10^-4 simplified in decimal form is 0.0001
