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Bob leaves school at the same time as Jane. Bob drives 4 mph faster than Jane. After 2 hours of driving in opposite directions, they are 116 miles apart. Let B represent the speed that B is driving so B-4 is Jane's speed.does this equation work 2(B+B - 4) = 116 O True O False

User Alex Lyman
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1 Answer

23 votes
23 votes

Solution:

Let the bob's speed be represented below as


=b

Since bob drives 4mph faster than jane, janes, speed will be represented below as


jane=b-4

The total speed will be calculated below as


b+b-4

The time taken is given below as


=2hrs

The total distance apart is given below as


=116mi

Concept:

Using the formula below, we will have


distance=speed* time

By substituting the values, we will have


\begin{gathered} distance=2(b+b-4) \\ 2(b+b-4)=116 \end{gathered}

By simplifying further, we will have


\begin{gathered} 2(b+b-4)=116 \\ 2(2b-4)=116 \\ 2b-4=(116)/(2) \\ 2b-4=58 \\ 2b=58+4 \\ (2b)/(2)=(62)/(2) \\ b=31mi\text{ }per\text{ }hr \end{gathered}

Substitute b=31 in the equation below


\begin{gathered} jane=b-4 \\ jane=31-4 \\ jane=27\text{ }mi\text{ }per\text{ }hr \end{gathered}

Hence,

Jane is driving at 27 miles per hour

Bob is driving at 31 miles per hour

The final answer is TRUE

User Zashu
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2.7k points