Mr. Jared asked his math students to compute the numerical value of (a+3). (a+6) for a particular positive value of a Ruby accidentally copied the expression as (a+3) a+6, so even though she used the correct value for a and did all computations correctly, she got the wrong answer. Similarly, Amber mistakenly wrote the expression as a+3. (a+6) and obtained an incorrect answer, despite making no other mistakes. Curiously, Ruby and Amber ended up with the same wrong answer! What was the correct answer to Mr. Jared'squestion?

Question

Carson Lyons

Mathematics

14 January, 13:58

Mr. Jared asked his math students to compute the numerical value of (a+3). (a+6) for a particular positive value of a Ruby accidentally copied the expression as (a+3) a+6, so even though she used the correct value for a and did all computations correctly, she got the wrong answer. Similarly, Amber mistakenly wrote the expression as a+3. (a+6) and obtained an incorrect answer, despite making no other mistakes. Curiously, Ruby and Amber ended up with the same wrong answer! What was the correct answer to Mr. Jared'squestion?

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Answers (1)

Know the Answer?

Ana Bright · Answer 1

The correct answer is 70.

Step-by-step explanation:

Since they got the same answer we have the equation:

(a + 3) a + 6 = a + 3 (a + 6)

a^2 + 3a + 6 = a + 3a + 18

a^2 + 3a - 3a - a + 6 - 18 = 0

a^2 - a - 12 = 0

(a - 4) (a + 3) = 0

So a = 4 or - 3.

As a is given as positive we take a = 4.

The correct numerical value =

(4 + 3) (4 + 6)

= 70.