Question

[Vũ Ngân Hà]

tính nhanh hộ mình mấy câu này với : ( ai nhanh mình sẽ tick cho )

;

\(\frac{0.24x450+0.8x15x3+3x3x8}{65-60+55-50+...+25-2.+5}\)

\(\frac{\left(23.4+19.5\right)x7+\left(23.4+19.5\right)x3+11}{0.55x2x30+5x11+2.75x8}\)

\(15\frac{3}{7}-5.35+\frac{3}{7}-2.41+\frac{3}{21}-1.24\)

Answer 1

[le bao truc]

a)
\(\frac{0,24x450+0.8x15x3+3x3x8}{65-60+55-50+...+25-2+5}\)
\(=\frac{0,24x45x10+0,8x45+3x3x8}{\left(65-60\right)+\left(55-50\right)+...+\left(25-20\right)+5}\)
\(=\frac{45\left(0,24x10+0,8\right)+3x3x8}{5+5+...+5}\)
\(=\frac{45x2,4+45x0,8+3x3x4x2}{5x6}\)

\(=\frac{108+36+36x2}{5x6}=\frac{36x3+36+36x2}{5x6}\)

\(=\frac{36\left(3+1+2\right)}{5x6}=\frac{36x6}{5x6}=\frac{36}{5}\)

Answer 2

[le bao truc]

b)
\(\frac{\left(23,4+19,5\right)\times7+\left(23,4+19,5\right)\times3+11}{0,55\times2\times30+5\times11+2,75\times8}\)

\(=\frac{\left(23,4+19,5\right)\times\left(7+3\right)+11}{1,1\times30+5\times11+2\times11}\)

\(=\frac{42,9\times10+11}{33+11\left(5+2\right)}=\frac{440}{33+77}=\frac{440}{110}=4\)

Cách này không hay lắm. Mong bạn thông cảm!