把右边式子A写成2,B写成2.5就可以算了,注意括号优先运算,答案应该是5.625
(2+2.5)÷(2÷2.5)=4.5÷0.8=5.625
2△2.5=(2+2.5)÷(2÷2.5)=4.5÷0.8=5.625
2+2.5=4.52/2.5=0.84.5/0.8=5.625