How do you multiply #(5 - 8y)^2#?

2 Answers
May 20, 2018

Answer:

Multiplying #(5-8y)^2# gives #64y^2-80y+25#

Explanation:

Ok, so we start by rewriting it as two separate binomials.

#(5-8y)(5-8y)#

So now we multiplying the two binomials by the FOIL method. we have and get

#25-40y-40y+64y^2#

So we would double check our work to ensure we didn't miss multiplying a number by another number, otherwise it wouldn't come out right. So we can combine like terms and get:

#25-80y+64y^2#

But, you would want to put it to the highest degree first as some people would want that.

So the final answer is:

#64y^2-80y+25#

May 20, 2018

Answer:

#(5-8y)^2 = (5-8y)(5-8y) = 64y^2 -80y +25#

Explanation:

To expand double brackets you need to multiply all of the terms in each bracket by the terms in the other bracket.

Applying the distributing rule #(a-b)^2 = a^2 - 2ab +b^2#)
So expanding this one you must do:

#-8y*-8y = 64y^2#
#(-8y*5)*2 = -80y#
and #5*5 = 25#

Add these terms together and you get the answer:

#64y^2 -80y +25#