Mathematics
Neha’s father is 28 years older than her. The product of their ages (in years) 4 years ago was 245. If present age of Neha is x years, then the algebraic representation of this information in the form of quadratic equation is:
x2 − 20x − 341 = 0
x2 + 20x − 341 = 0
x2 + 20x + 341 = 0
x2 − 20x + 341 = 0
Quadratic Equations
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Answer
Let Neha's present age be x and the age of her father be y.
Given,
Neha's father is 28 years older than her.
y = 28 + x ………(1)
Given,
Product of their ages 4 years ago was 245.
⇒ (x - 4)(y - 4) = 245 ………(2)
Substituting value of y from equation (1) in equation (2), we get :
⇒ (x - 4)(28 + x - 4) = 245
⇒ (x - 4)(x + 24) = 245
⇒ x2 + 24x - 4x - 96 = 245
⇒ x2 + 20x - 96 - 245 = 0
⇒ x2 + 20x - 341 = 0.
Hence, option 2 is the correct option.
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