Can you guys plz p. s can u show the work

18. 0.796 + 13 = 13.796 (the 13 is a whole number, so just put it in front of the decimal)

19. 15.63 + 24.36 = 39.99 (1+2=3 ; 5+4=9 ; 6+3=9 ; 3+6=9)

20. 19.86 - 4.94 = 14.92

21. 82 - 67.18 = 15.18 (again, whole number, there's no decimals to subtract, so leave them be)

22. 14.39 - 12.16 = 2.23 (1-1=0 ; 4-2=2 ; 3-1=2 ; 9-6=3)

what's that

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92