8+（-1/4）-5-（-0.25）=
=8-0.25-5+0.25
=8-5
=3
99*26=
=(100-1)*26
=100*26-1*26
=2600-26
=2574
（-3.5-7.75-4.25）÷1.1=
=(-3.5-12)÷1.1
=-15.5÷1.1
=-155/11