Answer:
Step-by-step explanation:
Step 1: We make the assumption that 160 is 100% since it is our output value.
Step 2: We next represent the value we seek with x.
Step 3: From step 1, it follows that 100%=160
Step 4: In the same vein, = x%=140.
Step 5: This gives us a pair of simple equations:
100%=160(1).
x%=140(2).
Step 6: By simply dividing equation 1 by equation 2 and taking note of the fact that both the LHS
(left hand side) of both equations have the same unit (%); we have
100% / x% = 160 / 140
Step 7: Taking the inverse (or reciprocal) of both sides yields
x% / 100% = 140 / 160
x% = 87.5%
therefore, 140 is 87.5% of 160
PART 1.
Going westward:
Distance: 2400 miles
Rate (this is speed): (450-wind_speed) mph
Time: distance / speed = 2400 / (450-wind speed)
Going eastward:
Distance: 2400 miles
Rate (this is speed): (450+wind_speed) mph
Time: distance / speed = 2400 / (450+wind speed)
PART 2
Formula for speed:
speed = distance / time
Now we solve this for time:
time = distance / speed
11h = 2400 / (450+-wind_speed)
+- sign is put because in one case wind increases speed of plane and in other case it decreases speed.
PART 3
To solve for wind_speed we start by rearranging formula so that we have wind_speed on left side:
(450+-wind_speed) = 2400 / 11
(450+-wind_speed) = 218mph
To fly this distance in 11h speed of plane must be 218mph.
The only way to get this solution is if we substract wind speed:
450-wind_speed = 218
wind_speed = 450-218 = 232mph
Answer:
c
Step-by-step explanation:
180= 45+ (5x+35)
-45 -45
135 = 5x + 35
-35 -35
100 = 5x
/5 /5
x=20
