1) 2-2+2-2=0;2/2*2/2=1;2/2+2/2=2;2-2/2+2=3;2+2-2+2=4;2+2+2/2=5;2*(2/2+2)=6;2+2+2+2=8;22/2-2=9;(22-2)/2=10
(còn số 7 không làm được)
2) a) \(52\cdot\frac{y}{78}=3380\)
\(52\cdot\frac{1}{78}\cdot y=3380\)
\(\frac{2}{3}\cdot y=3380\)
\(y=3380\div\frac{2}{3}=5070\)
b)\(55-y+33=76\)
\(88-y=76\)
\(y=88-76=12\)
3)\(3,54\cdot73+0,23\cdot25+3,54\cdot27+0,17\cdot25\)
\(=3,54\cdot\left(73+27\right)+25\cdot\left(0,27+0,13\right)\)
\(=3,54\cdot100+25\cdot0,4\)
\(=354+10=364\)