Let's say her speed was x miles/hour during the first 3 miles runThen, time = distance/speedt1 = 3/x eq1 In the next 4 miles run, her speed = x-1 miles/hourTime taken:t2 = 4/(x-1) eq2 Now, total time:t1 + t2 = 1 3/5 hourssubstitute t1 and t2 from eqs. 1 and 2 3/x + 4/(x-1) = 1 3/5=> 3/x + 4/(x-1) = 8/5
=> 3(x-1) + 4x = 8x(x-1)/5=> 35x - 15 = 8x2 - 8x=> 8x2 - 43x + 15 = 0=> (8x-3)*(x-5) = 0=> x = 3/8 or 5 miles/hourx can not be 3/8 miles/hour because in that case, the speed during 4 miles run would be 3/8-1 = negative numberi.e. speed during 3 miles segment = 5 miles/hourand speed during 4 miles segment = 5-1 = 4 miles/hour
The Lowest common multiple of 22 and 44 would be 22 because each of the numbers are divisible by it. So 22 / 22 = 1 and 44 / 22 = 2
Answer:
x=30
Step-by-step explanation:
2x=y-x
3x=y
2y=180
y=90
x=30.
Answer:
34 rounded is 30
Step-by-step explanation:
15 plus 15 is 30 30 plus 4 is 34
Answer:
r=56
Step-by-step explanation:
252= r * 4.5
r * 4.5 = 252
r * 4.5 * 10 = 252 * 10
45r = 2520
r = 56
