tính nhanh
145 + 145 x 2 + 145
=190+190
=380
145 + 145 x 2 + 145
= (145 + 145) + 145 x 2
= 290 + 290
= 580
hoặc
145 + 145 x 2 + 145
= 145 x (2 + 1 + 1)
= 145 x 4
= 580
\(145+145\cdot2+145=145\cdot1+145\cdot2+145\cdot1=145\cdot\left(1+2+1\right)=145\cdot4=580\)