How do you multiply #-5a (a-1)#?

1 Answer
Jul 1, 2015

Answer:

#-5a(a-1) = -25a^2+5a#

Explanation:

In general, the distributive property (of multiplication over subtraction) says:
#color(white)("XXXX")##m(p-q) =mp -mq#

Setting
#color(white)("XXXX")##m=(-5a)#
#color(white)("XXXX")##p=(5a)#
#color(white)("XXXX")##q= (1)#
this gives
#color(white)("XXXX")##(-5a)(5a) - (-5a)(1)#
#color(white)("XXXX")##=-25a^2 +5a#