Question

factorise : m^2+21m+90​

Answer 1

Answer:

m^2 + 21m+90

m^2 + 15m + 6m + 90

m(m+15) + 6(m +15)

(m+15) (m+6)

for zeroes -

i) m + 15 = 0

m= -15

ii) m+6= 0

m= -6

Answer 2

Answer:

I've done the sum, check the attachment