KHÔNG tính hãy so sánh:
a)45.16-17 với 28+45.15
b)7256.4375-725voi 3650+4375.7255
tính nhanh
\(\frac{\left(456.11+912\right).37}{13.74}\)
\(\frac{864.48-432.96}{864.48.432}\)
\(\frac{16.17-5}{16.16+11}\)
\(\frac{45.16-17}{28+45.15}\)
\(\frac{7256.4375-725}{3650+4375.7255}\)
\(\frac{\left(456.11+912\right).37}{13.74}\)
\(=\frac{\left(456.11+456.2\right).37}{13.37.2}\)
\(=\frac{[456.\left(11+2\right).37}{13.37.2}\)
\(=\frac{456.13}{13.2}\)
\(=\frac{456}{2}=228\)
Làm bằng cách nào cho hợp lí nhất :
a)\(\frac{16.17-5}{16.16+11}\)
b) \(\frac{45.16-17}{28+45.15}\)
c) \(\frac{7256.4375-725}{3650+4375.725}\)
chúc các bạn làm bài đúng nhất :))
a)\(\frac{16.17-5}{16.16+11}=\frac{16.17-16+11}{16.16+11}\)\(=\frac{16.\left(17-1\right)+11}{16.16+11}=\frac{16.16+11}{16.16+11}=1\)
b) \(\frac{45.16-17}{28+45.15}=\frac{45.\left(15+1\right)-17}{28+45.15}\)\(=\frac{45.15+45-17}{28+45.15}=\frac{45.15+28}{28+45.15}=1\)
c) \(\frac{7256.4375-725}{3650+4375.7255}=\frac{\left(7255+1\right).4375-725}{3650+4375.7255}\)\(=\frac{7255.4375+4375-725}{3650+4375.7255}\)\(=\frac{7255.4375+3650}{3650+4375.7255}=1\)
Câu C nhớ sửa 725 thành 7255 nha !
Bài giải
\(a,\text{ }\frac{16\cdot17-5}{16\cdot16+11}=\frac{16\cdot16+16-5}{16\cdot16+11}=\frac{16\cdot16+11}{16\cdot16+11}=1\)
\(b,\text{ }\frac{45\cdot16-17}{28+45\cdot15}=\frac{45\cdot15+45-17}{45\cdot15+28}=\frac{45\cdot15+28}{45\cdot15+28}=1\)
\(c,\text{ }\frac{7256\cdot4375-725}{3650+4375\cdot7255}=\frac{4375\cdot7255+4375-725}{4375\cdot7255+3650}=\frac{4375\cdot7255+3650}{4375\cdot7255+3650}=1\)
\(\dfrac{7256.4375-725}{3650+4375.7255}\)
tính nhanh
Ta có:
\( \dfrac{7256.4375-725}{3650+4375.7255}\\ =\dfrac{7255.4375+4375-7255}{3650+4375.7255}\\ =\dfrac{7255.4375+\left(4375-725\right)}{3650+4375.7255}\\ =\dfrac{7255.4375+3650}{3650+4375.7255}\\ =1\)
Vậy giá trị của \(\dfrac{7256.4375-725}{3650+4375.7255}=1\)
7256.4375-725=(7255+1).4375-725=7255.4375+4375-725=7255.4375+3650
⇒(7256.4375−725)/(3650+4375.7255)=(7255.4375+3650)/(3650+4375.7255)=1
7256.4375-725/3650+4375.7255
Ta có: \(7256.4375-\dfrac{725}{3650}+4375.7255\)
\(=7256.4375+4375.7255-\dfrac{29}{146}\)
\(=4375\left(7256-7255\right)-\dfrac{29}{146}\)
\(=4375.1-\dfrac{29}{146}\)
\(=\dfrac{638750}{126}-\dfrac{29}{126}\)
\(=\dfrac{638721}{126}=\dfrac{70969}{14}\)
Chúc bn học tốt!!!
Tính nhanh B= \(\frac{7256.4375-725}{3650+4375.7255}\)
\(B=\frac{7256.4375-725}{3650+4375.7255}=\frac{7255.4375+4375-725}{7255.4375+3650}=\frac{7255.4375+3650}{7255.4375+3650}=1\)
\(\frac{7256.4375}{3650+4375.7255}\)
\(\frac{7256.4375}{3650+4375.7255}\) = \(\frac{7256}{3650+7255}\) = \(\frac{1814}{2715}\)
\(\frac{7256.4375-725}{3650+4375.7255}\)
\(\frac{7256.4375-725}{3650+4375.7255}=\frac{\left(7255+1\right).4375-725}{3650+4375.7255}\)
\(=\frac{7255.4375+4375-725}{3650+4375.7255}\)
\(=\frac{7255.4375+3650}{3650+4375.7255}\)
\(=1\)
Ko tính giá trị hãy so sánh
A = 7256.4375 - 725
B = 3650 + 4375 . 7255
Tính:
\(\frac{7256.4375-725}{3650+4375.7255}\)(Lưu ý: dấu chấm là dấu nhân)
\(\frac{7256.4375-725}{3650+4375.7255}\)
\(=\frac{\left(7255+1\right).4375-725}{3650+4375.7255}\)
\(=\frac{7255.4375+4375-725}{3650+4375.7255}\)
\(=\frac{7255.4375+3650}{3650+4375.7255}\)
\(=1\)
\(\frac{7256.4375-725}{3650+4375.7255}=1\)
\(\frac{7256.4375-725}{3650+4375.7255}\)
\(=\frac{\left(7256-1\right).4375+4375-725}{3650+4375.7255}\)
\(=\frac{7255.4375+3650}{3650+4375.7255}\)
\(=1\)