5/12*(4,8a-1,2b)-3,6(4/9a-1/4b)=2a-0.5b-1.6a+0.9b=0.4a+0.4b
0.4a+0.4b=0.4(a+b)=0.4(<span>-2</span>)=-0.8
3*3*3*3*3 = 3 в 5 степени.