Tính hợp lí
Tính hợp lí
\(\left(-2021\right).\left(23+76\right)-2021=\left(-2021\right).99-2021=-202100\)
tính hợp lí
\(5,-\dfrac{2}{7}-\left(\dfrac{5}{11}-\dfrac{9}{7}\right)+\dfrac{5}{11}=-\dfrac{2}{7}-\dfrac{5}{11}+\dfrac{9}{7}+\dfrac{5}{11}=\left(-\dfrac{2}{7}+\dfrac{9}{7}\right)-\left(\dfrac{5}{11}-\dfrac{5}{11}\right)=1-0=1\\ 6,\dfrac{2}{3}+\dfrac{-2}{5}+\dfrac{-5}{6}-\dfrac{13}{10}=\left(\dfrac{4}{6}+\dfrac{-5}{6}\right)+\left(\dfrac{-4}{10}-\dfrac{13}{10}\right)=\dfrac{-1}{6}+\dfrac{-17}{10}=\dfrac{-5}{30}+\dfrac{-51}{30}=\dfrac{-56}{30}=\dfrac{-28}{15}\)
\(7,\dfrac{-5}{9}+\dfrac{8}{15}+\dfrac{4}{-9}+\dfrac{7}{15}=\left(\dfrac{-5}{9}+\dfrac{-4}{9}\right)+\left(\dfrac{8}{15}+\dfrac{7}{15}\right)=\left(-1\right)+1=0\\ 8,\left(\dfrac{12}{13}+7\right)-\left(-\dfrac{1}{13}+8\right)=\dfrac{12}{13}+7+\dfrac{1}{13}-8=\left(\dfrac{12}{13}+\dfrac{1}{13}\right)+\left(7-8\right)=1+\left(-1\right)=0\)
A)Tính cách hợp lí \(\frac{18x25x32}{9x16x50}\)
B) TÍnh cách hợp lí \(\frac{44x16x9}{3x22x8}\)
TÍNH HỢP LÍ NHA
tính hợp lí: 25.8.4.28.125
25.8.4.28.125
= 28.(25.4).(8.125)
= 28.100.1000
= 2800.1000
= 2800000
Câu 1: Tính hợp lí
Tham khảo: https://hoc247.net/hoi-dap/toan-6/tinh-a-b-voi-a-34-7-13-51-13-22-85-22-37-68-37-49-faq162600.html
\(C=\left(\dfrac{12}{199}+\dfrac{23}{200}-\dfrac{34}{201}\right).\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{6}\right)\)
\(C=\left(\dfrac{12}{199}+\dfrac{23}{200}-\dfrac{34}{201}\right).0\)
\(C=0\)
Bài 1. Tính hợp lí
Tính bằng cách hợp lí:
\(12,25+\left(-21,37\right)-\left(14,67-21,75\right)\)
\(=12,25-21,37-14,67+21,75\)
\(=12,25+21,75-21,37-14,63-0,04\)
\(=34-36-0,04\)
= -2-0,04=-2,04
Tính bằng cách hợp lí
120:{54-[50:2.(3^2-2.4)]}
= 120:{ 54-[25.(9-8)]}
= 120:{54-[25.1]}
= 120:{54-25}
= 120:29
=\(\dfrac{120}{29}\)