Tính bằng cách hợp lí a) 5/7 . -11/13 + 24/13 . 5/7 + 3 2/7
Giải thích
a) 57.−1113+2413.57+327=57.−1113+2413+237=57.1313+237=57+237=287=4.
b) −38:114+−38:117+235=−38.411+−38.711+135=−38.411+711+135=−38.1+135=−38+135=−1540+10440=8940.
a) 57.−1113+2413.57+327=57.−1113+2413+237=57.1313+237=57+237=287=4.
b) −38:114+−38:117+235=−38.411+−38.711+135=−38.411+711+135=−38.1+135=−38+135=−1540+10440=8940.