Answer:
336
Step-by-step explanation:
sec ( t ) cos ( t ) = (1/cos (t)) *cos(t) = 1
1
because the other arent right
-21
28
1) if r = -4
Substitute r = -4 in 3r - 9
= 3 * (-4) - 9
= -12 - 9
= -21
2) ( 4 / 7 ) * x = 16
4 * x = 16 * 7
x = 4 * 7
x = 28