Question

factorise m²-23m+42​

Answer 1

Step-by-step explanation:

m

${m}^{2} - 23m + 42$

${m}^{2} - 21m - 2m + 42 = 0$

$m(m - 21) - 2(m - 21) = 0$

$(m - 21)(m - 2) = 0$

$m - 21 = 0 \: \: \: or \: \: m - 2 = 0$

$m = 21 \: \: \: \: \: \: or \: \: \: \: \: \: m = 2$

Answer 2

${m}^{2} - (21 + 2) m+ 42 = 0 \\ {m}^{2} - 21m - 2m + 42 = 0 \\ m(m - 21) - 2(m - 21) = 0 \\ m - 21 = 0 \\ m = 21 \\ m - 2 = 0 \\ m = 2$