1.Tìm x, biết:

a.\(\frac{1}{2}\)x\(x\)+\(\frac{2}{3}\)=\(\frac{5}{2}\)

b.\(\frac{x}{12}\)+\(\frac{5}{24}\)=\(\frac{5}{6}\)

c.(1234+\(x\)+766)x0,25=6,2:0,01

2.Tính bằng cách hợp lý.

A=\(\frac{1}{2}\)x\(\frac{5}{7}\)+\(\frac{9}{7}\)x0,3+\(\frac{1}{2}\)x\(\frac{4}{7}\)+\(\frac{9}{4}\)+\(\frac{9}{7}\)x0.2

B=\(\frac{2002\cdot15-1}{2001+2002\cdot14}\)

1.Tìm x, biết:

a.\(\frac{1}{2}\)x\(x\)+\(\frac{2}{3}\)=\(\frac{5}{2}\)

b.\(\frac{x}{12}\)+\(\frac{5}{24}\)=\(\frac{5}{6}\)

c.(1234+\(x\)+766)x0,25=6,2:0,01

2.Tính bằng cách hợp lý.

A=\(\frac{1}{2}\)x\(\frac{5}{7}\)+\(\frac{9}{7}\)x0,3+\(\frac{1}{2}\)x\(\frac{4}{7}\)+\(\frac{9}{4}\)+\(\frac{9}{7}\)x0.2

B=\(\frac{2002\cdot15-1}{2001+2002\cdot14}\)

Đúng ghi Đ, sai khi S:

a,\(2\frac{2}{5}\)+\(1\frac{2}{5}\)=\(3\frac{2}{5}\)

b,\(6\frac{3}{4}\)-\(1\frac{1}{4}\)=\(5\frac{2}{4}\)

c,\(3\frac{1}{2}\)x\(2\frac{2}{3}\)=\(9\frac{1}{3}\)

d,\(4\frac{1}{6}\):\(2\frac{1}{5}\)=\(2\frac{5}{6}\)

Tính nhanh 

a, \(\frac{6}{9}\)+\(\frac{5}{7}\)+\(\frac{1}{3}\)

b, \(\frac{17}{7}\)+\(\frac{6}{5}\)- \(\frac{20}{14}\)

c , \(\frac{2}{5}\)x\(\frac{1}{4}\)+ \(\frac{3}{4}\)x\(\frac{2}{5}\)

d, \(\frac{6}{11}\):\(\frac{4}{6}\)+\(\frac{5}{11}\): \(\frac{2}{3}\)

Tính nhanh 

a, \(\frac{6}{9}\)+\(\frac{5}{7}\)+\(\frac{1}{3}\)

b, \(\frac{17}{7}\)+\(\frac{6}{5}\)- \(\frac{20}{14}\)

c , \(\frac{2}{5}\)x\(\frac{1}{4}\)+ \(\frac{3}{4}\)x\(\frac{2}{5}\)

d, \(\frac{6}{11}\):\(\frac{4}{6}\)+\(\frac{5}{11}\): \(\frac{2}{3}\)

Tìm\(\frac{a}{b}\)biết

\(\frac{2}{3}\)⁺\(\frac{a}{b}\)^{+\(\frac{1}{2}\)=\(\frac{23}{11}\)}

^{\(\frac{5}{6}\)-\(\frac{a}{b}\)+\(\frac{2}{3}\)=\(\frac{4}{3}\)}        (gấp nha)