Question

What value of 'a' will make x 2 - ax + 25 a perfect square?​

Answer 1

Answer : 10 ✔✔

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solution :

${x}^{2} - ax + 25 \\ \\ = > {(x)}^{2} - 2(x)(5) + {(5)}^{2} ....(1)$

It is the formula of :

${(a - b)}^{2} = {a}^{2} - 2ab + {b}^{2}$

where, a = x and b = 5

In question there is given that :

${x}^{2} - ax + 25...(2)$

On comparing equation (1) and (2) :

a = 2×5 = 10

So, the value of a will be 10 to make the equation is a perfect square and equation be like

${x}^{2} - 10x + 25 \\ \\ = > {(x - 5)}^{2}$

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I hope it will help you ☺

Fóllòw Më ❤