2 câu trả lời
Đáp án:
( a - 2 ) . b = -5
Do: a,b ∈ ZZ
→ a - 2; b ∈ ZZ
→ a - 2; b ∈ Ư_{(-5)} = {-1;1;5;-5}
Lập bảng giá trị
\begin{array}{|c|c|c|}\hline \text{a - 2}&\text{-1}&\text{1}&\text{-5}&\text{5}\\\hline \text{b}&\text{5}&\text{-5}&\text{1}&\text{-1}\\\hline \text{a}&\text{1}&\text{3}&\text{-3}&\text{7}\\\hline\end{array}
Vậy (a,b) = (1,5);(3; -5); (-3; 1); (7; -1)
#dariana
( a - 2 ) . b = -5
Vì : a,b ∈ ZZ
=> a - 2; b ∈ ZZ
=> a - 2; b ∈ Ư(-5) = {±1;±5}
Ta có bảng :
\begin{array}{|c|c|c|}\hline \text{a - 2}&\text{-1}&\text{1}&\text{-5}&\text{5}\\\hline \text{b}&\text{5}&\text{-5}&\text{1}&\text{-1}\\\hline \text{a}&\text{1}&\text{3}&\text{-3}&\text{7}\\\hline\end{array}
Vậy (a,b) = (1,5);(3; -5); (-3; 1); (7; -1)
Câu hỏi trong lớp
Xem thêm