How do you multiply #(5n-4)^2#?

2 Answers
Jun 9, 2017

Answer:

#25n^2 - 40 n + 16#

Explanation:

#(a + b)^2 = a^2 + 2ab + b^2#

#(5n + (-4))^2 = (5n)^2 + 2*5n*(-4) + (-4)^2#

Jun 9, 2017

Answer:

#25n^2-40n+16#

Explanation:

#"express " (5n-4)^2=(5n-4)(5n-4)#

#"each term in the second bracket is multiplied by each term"#
#"in the first bracket as shown below"#

#(color(red)(5n-4))(5n-4)#

#=color(red)(5n)(5n-4)color(red)(-4)(5n-4)#

#"distributing gives"#

#=(color(red)(5n)xx5n)+(color(red)(5n)xx-4)+(color(red)(-4)xx5n)+(color(red)(-4)xx-4)#

#=25n^2-20n-20n+16larr" collect like terms"#

#=25n^2-40n+16#