Question

Question 21

Factorised form of $p^2-17p-38$ is
a) $(p-19)(p+2)$
b) $(p-19)(p-2)$
c) $(p+19)(p+2)$
d) $(p+19)(p-2)$

Answer 1

a) $(p-19)(p+2)$
$\to$​​​​​​​We have, $p^2-17p-38=p^2-19p+2p-38$
[by spliting the middle term, so that the product of their numerical coefficients is equal to the constant term]
$=p(p-19)+2(p-19)=(p-19)(p+2)[\because x^2+(a+b)x+ab=(x+a\left)\right(x+b\left)\right]$