q和-3q是不是也是like terms?

Any 2 terms : 要有一樣的‧ variable( 如 : q, q², q⁻¹, ..... ) , 才是 like terms.
為什麽 ? --- ∵ variable 相同, 才可以 相加 ; 正如 :-

i) q + (-3q) = -2q → : q, -3q are like terms

ii) q + 2⁴q = (1+2⁴)q = 17q → : q, 2⁴q are like terms

iii) q + (√5)q = (1+√5)q → : q, (√5) q are like terms

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相反地, if 2 terms have 不相同 的 variable, 就不可 相加 --- 稱為 unlike terms

For eg. :-
q , q² --- unlike terms

q , 1/q --- unlike terms { ∵ 1/q = q⁻¹ }

q , √q --- unlike terms