Question

factorise a²-10a+21
plz answer me step by step

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Answer 1

Answer:

a²-10a+21

=a²-3a-7a+21

=(a²-3a)-(7a+21)

=a(a-3)-7(a-3)

=(a-3)(a-7)

Answer 2

Answer:

${a}^{2} - 10a + 21$

${a}^{2} - (7 + 3)a \: + 21$

${a}^{2} - 7a \: - 3a \: + 21$

=> a(a - 7) - 3(a -7)

=> (a - 7)(a - 3)

Ans. (a - 3)(a - 7)

Hope it helps.