Answer:
cos x (2 sin x − 1)
Step-by-step explanation:
sin(2x) − cos x
Use double angle formula.
2 sin x cos x − cos x
Factor.
cos x (2 sin x − 1)
Answer:
-1
Step-by-step explanation:
-5-15+4+15
=-20+19
=-1
9514 1404 393
Answer:
DE = 86
EF = 84
Step-by-step explanation:
We assume that point E lies on segment DF, so that ...
DE + EF = DF
(3x +20) +(2x +40) = 170
5x = 110 . . . . . . . . . . . . . . . collect terms, subtract 60
x = 22 . . . . . . . . . . . . divide by 5
DE = 3×22 +20 = 66 +20 = 86
EF = 2×22 +40 = 44 +40 = 84
Because the factor would divide it into two
