(1)(x+p)(x+q) (2)①(m+9)(m-2)②(x-5)(x+3)
(1)x 2+(p+q)x+pq=(x+p)(x+q)
(2)①m 2+7m-18
=m 2+(9-2)m+(-2)×9
=(m+9)(m-2)
②x 2-2x-15
=x 2+(-5+3)x+(-5)×3
=(x-5)(x+3)
(1)(x+p)(x+q) (2)①(m+9)(m-2)②(x-5)(x+3)
(1)x 2+(p+q)x+pq=(x+p)(x+q)
(2)①m 2+7m-18
=m 2+(9-2)m+(-2)×9
=(m+9)(m-2)
②x 2-2x-15
=x 2+(-5+3)x+(-5)×3
=(x-5)(x+3)