Because you wrote a lot less when writing it this way. Groups of terms beside each other are multiplying each other and you have to solve what’s inside of those groups before multiplying them together.
Groups of terms beside each other are multiplying each other
Actually the whole thing is a single Term. Terms are separated by operators and joined by grouping symbols, and there’s no operators between the successive brackets.
you have to solve what’s inside of those groups before multiplying them together
You don’t have to, but it sure makes the working-out a lot easier if you do!
Because you wrote a lot less when writing it this way. Groups of terms beside each other are multiplying each other and you have to solve what’s inside of those groups before multiplying them together.
Actually the whole thing is a single Term. Terms are separated by operators and joined by grouping symbols, and there’s no operators between the successive brackets.
You don’t have to, but it sure makes the working-out a lot easier if you do!
If a=1, b=2, c=3, d=4, then…
(a+b)(c+d)=(ac+ad+bc+bd)
(1+2)(3+4)=(1x3+1x4+2x3+2x4)=(3+4+6+8)=21
whereas…
(1+2)(3+4)=(3)(7)=(3x7)=21 :-)