Question

m²-11=0 Solve this quadratic equation by factorisation.

Answer 1

Hey!

Here is your answer!
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${m}^{2} - 11 = 0 \\ \\ {(m)}^{2} - {( \sqrt{11} )}^{2} = 0 \\ \\ using \: {a}^{2} - {b}^{2} = (a + b)(a - b) \\ \\ (m + \sqrt{11} )(m - \sqrt{11} ) = 0 \\ \\ when \: \: \: \: m + \sqrt{11} = 0 \\ \\ m = - \sqrt{11} \\ \\ when \: \: \: \: m - \sqrt{11} = 0 \\ \\ m = \sqrt{11}$
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Hope it's satisfactory!

Answer 2

Hey there!

We're asked to find the value of m by factorisation.

We will use : a² - b² = ( a + b) ( a - b)

m² - 11 = 0

m² - (√11)² = 0

( m - √11 ) ( m + √11 ) = 0

Now the following cases arise :

1) m - √11 = 0 / ( m + √11 )

2)m + √11 = 0 / ( m - √11 )

1) =>
m - √11 = 0
m = √11

2) =>
m + √11 = 0
m = -√11 .

So, m = -√11 , √11

Hope helped!