7/13.7/15 -5/12.21/39+49/91.8/15
tính nhanh 7/13.7/15-5/12.21/39+49/91.8/15
Tính nhanh:7/13.7/15-5/12.21/39+49/91.8/15
tính nhanh :
a.7/13.7/15-5/12.21/39+49/91.8/15
nhớ trả lời sớm nhất cho mình nhé! Thank you .
tính giá trị biểu thức(hợp lí nếu có):
a,7/13.7/15-5/12.21/39+49/91.8/15
b,(1+2/1/3-3/1/4):(1+3/7/12-4/1/2)
tinh nhanh 7/12.7.15-5/12.21/39+49/91.8/15
Tính nhanh:
7/13.7/15-5/12.21/39+49/51.8/15
\(\left(7^{15}.4+13.7^{15}\right):7^{16}\)
7 phần 13 x 7 phần 15 - 5 phần 12 x 21 phần 39 + 49 phần 91 x 8 phần 15
TINH NHANH
7/13 . 7/15 - 5/12 . 21/39 + 49/91 . 8/5
\(\frac{7}{13}.\left(\frac{7}{12}\right)-\frac{5}{12}.\left(\frac{21}{39}\right)+\frac{49}{91}.\left(\frac{8}{5}\right)=\frac{7}{13}.\left(\frac{7}{12}\right)-\frac{5}{12}.\left(\frac{7}{13}\right)+\frac{7}{13}.\left(\frac{8}{5}\right)=\frac{7}{13}.\left(\frac{7}{15}-\frac{5}{12}+\frac{8}{5}\right)=\frac{7}{13}.\left(\frac{33}{20}\right)=\frac{261}{260}\)