Remove brackets
a×(b+c)
=a×b+a×c distribution rate
(a×b)×c=a×(b×c), associative law ① commutative law of addition.
a+b = b+ a；
② the associative law of addition
a+(b+ c)=(a+b)+c；
(3) there is a number of 0, so that
0+a = a+0 = a；
(4) Any rational number other than 0, whose power of 0 is equal to1;
⑤ Multiplicative commutative law
ab = ba
⑥ Multiplicative associative law
a(BC)=(ab)c；
⑦ distribution law
a(b+ c)= a b+ AC；
⑧ Multiplication has a unit 1≠0, so that for any rational number A,1a = a1= a;
Pet-name ruby For rational number A which is not 0, there is a multiplication inverse 1/a, so a (1/a) = (1/a) A =1.
⑩0a=0
Text explanation: A number multiplied by 0 still equals this number.
Exponential addition of power multiplication with the same base
Exponential difference of the same base power fraction