# Thread: Special Products, square of a binomial

1. ## Special Products, square of a binomial

OK I have an assignment due tomorrow and I'm pretty much screwed. This is the first problem I have. The solution is given, I just can't understand how to get said solution. Usually I just take a look at an example and don't have problems with the rest of the questions, but I can't figure this out.

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

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

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

The first line is obvious. However, I am completely lost on where to go from there. Could someone please try to explain to me the steps I need to take to solve this problem

OK guys it came to me, but I may still have problems with the more advanced questions.

3. Originally Posted by Badmath
OK I have an assignment due tomorrow and I'm pretty much screwed. This is the first problem I have. The solution is given, I just can't understand how to get said solution. Usually I just take a look at an example and don't have problems with the rest of the questions, but I can't figure this out.

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

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

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

The first line is obvious. However, I am completely lost on where to go from there. Could someone please try to explain to me the steps I need to take to solve this problem
what is the problem? you're just expanding correct?

take one term in the first set of brackets and multiply every term in the second set. then take the next term in the first set of brackets and multiply everything in the second set...

$(a + b)^2 = ( {\color {red}a} + {\color {blue}b})(a + b) = {\color {red}a}(a) + {\color {red}a}(b) + {\color {blue}b}(a) + {\color {blue}b}(b) = a^2 + 2ab + b^2$

A better way is to remember the formula for squaring binomials.

In general, $(a \pm b)^2 = a^2 \pm 2ab + b^2$