Question

the cost of a chocolate is Rs (4+y) an mohit bought (4+y) chocolates. find the amount paid by him in terms of y. if y=10 , find the amount paid by him .
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Answer 1

Cost of 1 chocolate = x + 4 Cost of (x + 4) chocolate = (x + 4)(x + 4) = x2 + 8xy + 16 = (10)2 + 10 + 16 = 100 + 80 + 16 = 196

Answer 2

Answer:

$x {}^{2} + xy + xy + y {}^{2} . \\ = x {}^{2} + 2xy +y {}^{2} . \\ when \: x = 10 \: and \: y = 5. \\ (10) {}^{2} + 2(10)(5) + (5) {}^{2} \\ = 100 + 100 + 25 \\ = 225.$