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Which constant must be added and subtracted to solve the quadratic equation 9x2 + 3/4xâ€"" 2 = 0 by the method of completing the square? (A) 1/8 (B) 1/64 (C) 1/4 (D) 9/64 NCERT Class X Mathematics - Exemplar Problems Chapter _QUADRATIC EQUATIONS

User Mdew
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To solve the quadratic equation 9x^2 + 3/4x - 2 = 0 by the method of completing the square, we should figure out what constant must be added and subtracted.

The process looks like this:

Firstly, we identify the coefficient of the x term, which is 'b', in our case it is 3/4.

The formula to calculate the term to add and subtract to complete the square is (b/2)^2.

So we take 3/4 and halve it to get 3/8

Next, we square this value. When (3/8)^2 = 0.140625 or 9/64.

So, to make it a perfect square, we must add and subtract 0.140625 or 9/64 from the equation 9x^2 + 3/4x - 2 = 0.

So, the answer is (D) 9/64.

User DxTx
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