Question

Cau 1: Tinh

a,    \(\frac{3}{5}-\frac{5}{6}\)  

b,     \(\left(\frac{3}{4}+\frac{-7}{2}\right).\left(\frac{2}{11}+\frac{6}{11}\right)\)

c,      25% cua A voi A=\(\frac{4}{3}.\frac{13}{9}-\frac{4}{3}.\frac{40}{9}\)

 Cau 2 : Tim x biet 

a,     x-\(\frac{3}{4}=\frac{-1}{2}\)   

b,     \(\frac{x+2}{3}=\frac{x-2}{2}\) 

Cau 3:Lop 6A co 45 hoc sinh. So hoc sing gioi bang 20% so hoc sinh ca lop. So hoc sinh kha gap 3 lan so hoc sinh gioi. Con lai la hoc sing trung binh.

a,     Tinh so hoc sinh moi loai cua lop 6A

b,     Tinh ti so phan tram so hoc sinh trung binh  so voi so hoc sinh ca lop.