Math, asked by visheshrathorepbpa2c, 1 year ago

Rekha is 3 year older than anita.five year ago Rekha's age was foyr times Anita's age.find the ages of Rekha and Anita.

Answers

Answered by Anushka12339
1
Let’s say that the present age of Marina’s daughter is ‘x’ years. Then 4 years ago, her age was (x - 4) years. Therefore, Marina’s age 4 years ago was: (x - 4) + 3(x - 4) = 4(x - 4) years. 6 years from now, the daughter’s age will be (x + 6) years, and Marina’s age will be: 2(x + 6) years.

Now, 6 years from now will be (6+4), i.e., 10 years away from 4 years ago. Thus, Marina’s age 6 years from now can also be written as 4(x - 4) + 10 = (4x - 6) years. Therefore, 2(x + 6) = 4x - 6.

Or, 2x + 12 = 4x - 6.

Or, 2x = 18.

Thus, the daughter’s age (x) = 9 years, and Marina’s present age = 4(x - 4) + 4 = 24 years.

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Definitions:

Let D be the daughter’s age

and

M be Marina’s age.

Four years ago equation derivation:

Looking back four years ago, this means we have D-4 and M-4.

In the statement, Marina was 3 times older than her daughter. From this statement, we would say M=3D.

However, we are four years in the past. So, our M and D in the formula above are replaced with M-4 and D-4, respectively.

So, our formula for Marina being 3 times older than her Daughter is:

3(D-4) = M-4→ 3D-12=M-4→3D=M+8 [1]

Six years from now equation derivation:

Following the same thought process above, you get the equation:

2(D+6) = M+6→2D+12=M+6→2D=M-6 [2]

Solve for D and M using Systems of Equation:

We have equations [1] and [2] below:

3D=M+8

2D=M-6

Looking at 2D=M-6, we have D=(M-6)/2 by some operations.

Plug in D=(M-6)/2 into 3D=M+8 and solve for M.

M should be 34.

I'll leave D to be solved by you.

7.2k Views · · Answer requested by
Let Marina’s age be x and her daughter’s age y.

Let us form equations for 4years ago ratio.

x-4=3(y-4)....
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