3. Tìm x

\(a)\,\,75 \times x = 1800\)                        \(b)\,\,1855:x = 35\)

Lời Giải:

3. 

\(\eqalign{
& a)\,\,75 \times x = 1800 \cr
& \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = 124800:75 \cr
& \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = 24\cr
& b)\,\,1855:x = 35 \cr
& \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = 1855:35 \cr
& \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = 53 \cr} \)