Question

how to split middle term??

Answer 1

the middle term is to be splitted in such a way that the product of two numbers gives the c term in the equation and there sum gives the middle term.so we can replace middle term by these 2 numbers.
for example 
if 10 is the middle term and 7 is the c term
then 10 can be written as the product of 2*5 and the sum of the numbers gives the third term 7

Answer 2

First multiply a & c then see the sign of the last term then factor the product of a & c to bring b then make two brackets that should be same so that we can take common that bracket the two brackets we will get put one by one these brackets equal to 0 we will get two factors of x