Question

convert seven years ago varun's age was five times the square of swati's age into equation​

Answer 1

Answer:

varun-27

swati-9

Step-by-step explanation:

Let the present age of Varun and Swati are x and y years respectively.

Given – 7 years ago

x – 7 = 5(y-7)^2 ----------------1

Also given – 3 years hence

y + 3 = 2/5 (x + 3)

5y + 15 = 2x + 6

2x = 5y + 9

x = (5y + 9)/2 ------------------2

Substitute the value of x in equation 1

(5y + 9)/2 – 7 = 5 (y-7)^2

5y + 9 – 14 = 10 (y^2 – 14y + 49)

5y – 5 = 10y^2 – 140y + 490

10y^2 – 145y + 495 = 0

Dividing the equation by 5

2y^2 – 29y + 99 = 0

Solving above quadratic equation to find y

y = (-b + sqrt (b^2 – 4ac))/4ac or y = (-b - sqrt (b^2 – 4ac))/4ac

get y = 9 and y = 11/2

consider age as a whole number

Therefore, y = 9 years

Substitute the value of y in equation 2

Therefore, x = (5 * 9 + 9)/ 2 = 27 years

Answer – The present age of Varun is 27 years and present

age of Swati is 9 years.

Answer 2

Answer:

Step-by-step explanation:

Let Varun's age be x

Swati's age be y

7 years ago

Varun's age=x-7

Swati's age =y-7

x-7=5(y-7)^2

x-7=5(y^2-49)

x-7=5y^2 - 245