Question

Construct a word problem on quadratic equation so that one answer will be 15
(age, metres, speed, rupees, etc). Solve the problem you have constructed.​

Answer 1

ANSWER:

Question:

The present age of Ravi is such that if it is squared, it will be equal to 30 more than 13 times his present age. Find his present age.

Solution:

Let Ravi's present age be x years.

According to the given condition,

x^2 = 13x + 30

x^2 - 13x - 30 = 0

x^2 - (15x - 2x) - 30 = 0

x^2 - 15x + 2x - 30 = 0

x (x - 15) + 2 (x - 15) = 0

(x + 2) ( x - 15) = 0

x + 2 = 0 OR x - 15 = 0

x = (-2) OR x = 15

x ≠ (-2) as age can never be negative.

Therefore, x = 15.

Therefore, Ravi's present age is 15 years.

I hope this helps! Please comment if there are any mistakes!!

Answer 2

Given,

word suggestion for word problem ( age, meters, speed, rupees, etc).

To Find,

the word problem whose one answer is 15.

Solution,

word problem: the present age of Rajesh is such that if it is squared, it will be equal to 30 more than 13 times and his present age. Find his present age.

The present age of Rajesh is:

let Rajesh's present age be x years,

according to the word problem,

$x^{2} = 13x + 30\\\\x^{2} - 13x -30 =0\\\\x^{2} -(15x-2x) - 30=0\\\\x^{2} -15x+2x-30=0\\\\x(x-15)+2(x-15)=0\\\\(x+2)(x-15)=0\\\\x+2=0, x-15=0\\\\x=-2,x=15$

x≠ -2 because age can not be negative.

therefore, the x=15 is the required answer.

Hence the present age of Rajesh is 15.