Use an appropriate identity to find the exact value of the expression.
cos(310)cos(50)-sin(310)sin(50)

We know that cos(a+b) = coa.cob-sia.sinb

cos(310+50) = coas(310).cos(50) -sin(310).sin(50)

1st) cos(310+50) cos(360) = 1

2nd) cos (310) = cos(50)  and sin(310) = -sin(50)

3rd) 1= cos²(50) - [-sin²(50)]

1= cos²(50) + sin²(50)
 , which is 1

I’m guessing that the answer is c, but i’m not sure which grid is being talked about. since 5x5= 25 and 3x3= 9 (which there are no answers for). a is not right because while the ratio is the same, 6/25= 0.24 which is equal to 24% not 30%.

25 inches - 0.694 yards