Question

Đơn giản biểu thức sau :

B= \(\frac{\frac{12}{13}+\frac{12}{1313}+\frac{12}{131}-\frac{12}{1313}}{\frac{15}{13}+\frac{15}{131}-\frac{15}{1313}+\frac{15}{1313}}\)

HELPME

Answer 1

=>B=\(\frac{12.\left(\frac{1}{13}+\frac{1}{1313}+\frac{1}{131}+\frac{1}{1313}\right)}{15.\left(\frac{1}{13}+\frac{1}{1313}+\frac{1}{131}+\frac{1}{1313}\right)}\)

=>B=\(\frac{12}{15}\)

=>B=\(\frac{4}{5}\)

Answer 2

B = \(\frac{12.\left(\frac{1}{13}+\frac{1}{1313}+\frac{1}{131}-\frac{1}{1313}\right)}{15.\left(\frac{1}{13}+\frac{1}{131}-\frac{1}{1313}+\frac{1}{1313}\right)}\)

=\(\frac{12.\left(\frac{1}{13}+\frac{1}{131}\right)}{15.\left(\frac{1}{13}+\frac{1}{131}\right)}\)

=\(\frac{12}{15}=\frac{4}{5}\)

Vậy B = 4/5.

Answer 3

B=\(\frac{\frac{12}{13}+\frac{12}{1313}+\frac{12}{131}-\frac{13}{1313}}{\frac{15}{13}+\frac{15}{131}-\frac{15}{1313}+\frac{15}{1313}}\)

B=\(\frac{\frac{12}{13}+\frac{12}{131}}{\frac{15}{13}+\frac{15}{131}}\)

B=\(\frac{12\cdot\left(\frac{1}{13}+\frac{1}{131}\right)}{15\cdot\left(\frac{1}{13}+\frac{1}{131}\right)}\)

Chia cả tử và mẫu B cho \(\frac{1}{13}\)+\(\frac{1}{131}\)(rút gọn phân số)

Ta được:B=\(\frac{12}{15}\)=\(\frac{4}{5}\)