If he bikes for 10 miles per hour and 8 miles per hour for the same distance x miles, he went 10 miles per hour for x/10 hours, as Distance = Rate*Time and on the way back he would go for x/8 hours. So then he went 2x distance, in x/8 + x/10 hours. Since x/8 + x/10 = 10x/80 + 8x/80 = 18x/80 = 9x/40, he went 2x miles in 9x/40 hours. this can be converted into a rate with the above equation Distance = Rate*Time, so 2x=(9x/40) * Rate, thus we divide by 9x/40 on both sides to get 80x/9x = Rate, the x cancels out, and we get 80/9 Miles per hour.
The answer is unreasonable because the value of x is between 2 and 3.The error is : she did not introducing logs in solving the equation.
Step-by-step explanation:
The question is 
Here answers is unreasonable because, she can test with powers of seven like;
7²=49
7³=343
So this means the value of x lies between 2 and 3, so here answer 11.71 is unreasonable
b) In this case, to solve the equation, introduce logs both sides


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Keywords :Equation, error
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Answer: why you need to know???
Step-by-step explanation:
Sus
3/10 is the answer
i am not sure if the answer is wrong i am sorry