For all of these we will use the Order of Operations, also known as PEMDAS, then compare the simplifed values to see if they are equal.
[a] Equivalent / Verified
(-5) * [(-7) + (-5)] = [(-5) * (-7)] + [(-5) * (-5)]
(-5) * [-12] = [35] + [25]
60 = 60
[b] Equivalent / Verified
(-7) * [(-8) + 9] = [-7 * (-8)] + [(-7) * 9]
(-7) * [1] = [56] + [-63]
-7 = -7
[c] Equivalent / Verified
(-25) * [(-7) + (-15)] = [(-25) * (-7)] + [(-25) * (-15)]
(-25) * [-22] = [175] + [375]
550 = 550
Answer:
Bus speed: 22 mph; Trolley speed: 14 mph
Step-by-step explanation:
Let rb represent the speed of the bus and rt the speed of the trolley. Then rb = rt + 8 (mph).
Recall that distance = rate times time. Two different distances and two different speeds are involved here, but only one time.
Thus,
60 mi 44 mi
--------------------- = time (same in both cases) = -------------
rt + 8 mi/hr rt
Cross-multiplying, we get 44rt + 8(44) = 60 rt, or
352 = 16rt.
Solving this for rt, we get rt = speed of bus = 352/16 = 22 mph
The speed at which the bus travels is 22 mph and that at which the trolley travels is (22 mph - 8 mph) = 14 mph
Answer:
A = 50.24
Step-by-step explanation:
Diameter = 8
8/2 = 4
4 is the radius
A = πr2
A = 3.14 x 42
4 x 4 = 16
A = 3.14 x 16
A = 50.24