If a – b = 3 and a2 – b2 = 25, then find the sum of both the variables ‘a’ and ‘b’

If a – b = 3 and a2 – b2 = 25, then find the sum of both the variables ‘a’
and ‘b’

Here is my answers options. Which one is correct?
a. 8.6
b. 3.5
c. 2.4
d. 8.33
e. 3.88

Please help me by salving this GMAT Questions.
Thanks.

Default Asked on October 13, 2017 in GMAT.
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1 Answer(s)

    Thanks for your questions. Your problem was –

    If a – b = 3 and a2 – b2 = 25, then find the sum of both the variables ‘a’ and ‘b’

    Correct answer: d

    Let’s we see how?

    I’m trying to solve your problem and explain in details.  now let’s see –

    Your question’s details Explanation:

    We know the standard algebraic formula for (a)2 – (b)2
    (a)2 – (b)2 = (a + b) (a – b)
    Now, according to the data given in the question, a – b = 3 and a2 – b2 = 25.
    Substituting these values in above equation, we get,
    25 = (a + b) (3)
    ∴ (a + b) = 25/3
    ∴ a + b = 8.3333
    Hence, the correct answer is option d.

    Hope you can understand easily. If this is useful for you, then share to your friends on facebook, twitter and google plus. and visit from my website http://KnowledgeWorldbd.com
    Thanks.

    Brong Answered on October 17, 2017.
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