Đề bài

Điền số thích hợp vào bảng sau:

a	\(\dfrac{1}{5}\)	\(\dfrac{12}{17}\)	\(\dfrac{3}{4}\)	\(\dfrac{-7}{30}\)	\(\dfrac{2}{3}\)
b	\(\dfrac{4}{5}\)	\(\dfrac{-21}{17}\)	\(\dfrac{5}{12}\)	\(\dfrac{8}{45}\)	\(\dfrac{5}{4}\)
a+b
a-b

Lời giải chi tiết

a	\(\dfrac{1}{5}\)	\(\dfrac{12}{17}\)	\(\dfrac{3}{4}\)	\(\dfrac{-7}{30}\)	\(\dfrac{2}{3}\)
b	\(\dfrac{4}{5}\)	\(\dfrac{-21}{17}\)	\(\dfrac{5}{12}\)	\(\dfrac{8}{45}\)	\(\dfrac{5}{4}\)
a+b	1	\(\dfrac{-9}{17}\)	\(\dfrac{7}{6}\)	\(\dfrac{-1}{18}\)	\(\dfrac{23}{12}\)
a-b	\(\dfrac{-3}{5}\)	\(\dfrac{33}{17}\)	\(\dfrac{1}{3}\)	\(\dfrac{-37}{90}\)	\(\dfrac{-7}{12}\)