Question

(m-1)²-8(m-1)+12
help me in this sum
majab​

Answer 1

Answer:

Question

solve the sum :-

(m-1)²-8(m-1)+12

Solution

identity used -

${ \underline{ \boxed{ \sf {(a - b)}^{2} = {a}^{2} + {b}^{2} - 2ab }}}$

Now

$\sf{ \implies{ {(m - 1)}^{2} = {m}^{2} + 1 - 2m}}$

Add

$\sf{ \implies \: {m}^{2} + 1 - 2m - 8(m - 1) + 12} \\ \\ \sf{ \implies {m}^{2} + 1 - 2m - 8m + 8 + 12} \\ \\ \sf{ \implies \: {m}^{2} - 10m + 21}$

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MORE TO KNOW !!

✏️(a+b)²= a²+b²+2ab

✏️(a-b) ²= a²+b²-2ab

✏️ (a+b) (a-b) = a²-b²

✏️(x + y)³= x³ + y³ + 3xy(x + y)

✏️(x – y)³ = x³– y³ – 3xy(x – y)

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