• GreyBeard@lemmy.one
    link
    fedilink
    English
    arrow-up
    136
    arrow-down
    1
    ·
    1 day ago

    For those of you who were confused even after reading the comments: (a)(b) basically means a*b. My mind just didn’t connect that to the fact that (x-x)=0. in the (a-x)(b-x) stuff is also (x-x) which = 0, and anything * 0 = 0, so no matter the value of literally everything else in the equation, it all equals out to 0 because every single () will get multiplied by (x-x), which is 0. There, hopefully that will clear it up for anyone remaining lost. And like all good jokes, they are always best when you have to explain them.

      • GreyBeard@lemmy.one
        link
        fedilink
        English
        arrow-up
        5
        ·
        6 hours ago

        To expand on what superkret said, in math there is the concept of “order of operations”. That is to say, every function in math (add, multiply, divide) has to be done in a specific order. Since multiplication comes before addition and subtraction, if you have a formula like a-xb-x, you will do xb first, then a minus the result of x*b, which would give a very different result than if you did a-x and multiplied that by b-x. This is where the parenthesis come in. You are basically saying, resolve every section in parenthesis first using the proper order, then resolve the rest.

        My original example (a)(b) was over simplified, because there is no conflict there. You can also do things like (ax)-(bx). If there is no operator though, it is assumed multiplication, and I’m unsure why that is.

      • superkret@feddit.org
        link
        fedilink
        English
        arrow-up
        13
        ·
        8 hours ago

        To make sure what’s inside the brackets is resolved internally before they’re multiplied with each other.

         (a)  (b)   =   a * b  
        (a+1)(b+1) =/= a+1*b+1