Question

26. Cost of (3x + 4y) Fast track reflex 2.0 watches cost Rs.12x2 + 7xy – 12y2. What will be

cost of one such watch? Also, find the cost of (x + y) watches of the same model.​

Answer 1

Given info : Cost of (3x + 4y) Fast track reflex 2.0 watches cost Rs. 12x² + 7xy - 12y².

To find : what will be the cost of one such watch and also find the cost of (x + y) watches of the same model ?

solution : cost of (3x + 4y) watches = 12x² + 7xy - 12y²

so cost of 1 watch = (12x² + 7xy - 12y²)/(3x + 4y)

= {12x² + 16xy - 9xy - 12y²}/(3x + 4y)

= {4x(3x + 4y) - 3y(3x + 4y)}/(3x + 4y)

= (4x - 3y)(3x + 4y)/(3x + 4y)

= (4x - 3y)

Therefore the price of each watch is (4x - 3y)

now price of (x + y) watches = (x + y)(4x - 3y)

= 4x² - 3xy + 4xy - 3y²

= 4x² + xy - 3y²

Answer 2

Answer:

Hope it help you

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