1)5+4+3=12
2)12×5=60
3) 60+1,2=61,2
4) 12×4=48
5) 12×3=36
6) 61,2+48+36=145,2
<span>0=0</span>
<span><span>10−10</span>=<span>15−15</span></span>
<span><span><span>10−6</span>−4</span>=<span><span>15−9</span>−6</span></span>
<span><span>2<span>(<span><span>5−3</span>−2</span>)</span></span>=<span>3<span>(<span><span>5−3</span>−2</span>)</span></span></span>
<span>2=3</span>
<span><span>2+2</span>=<span>3+2</span></span>
<span><span>2+2</span>=<span>5</span></span>