Answer:
3 - (-7)
= 3 + 7.
Step-by-step explanation:
A double negative is equivalent to a plus.
Answer:
sin 2x + cos x = 2 sin x cos x + cos x = (2 sin x + 1)cos x
Step-by-step explanation:
Given the expression: sin 2x + cos x,
then we can use the formula: sin 2x = 2 sin x cos x, which gives:
sin 2x + cos x = 2 sin x cos x + cos x = (2 sin x + 1)cos x
So there you have two expressions in terms of sin x and cos x, as requested. :D
Given:
unit rate: 20km/h
Speed = distance / time
20kmh = 30km / time
time = 20kmh / 30km
time = 2/3 hrs or 40 minutes
2/3 hrs * 60mins/hr = (2*60)/3 = 120/3 = 40 minutes
