(+8又十分之七)÷(-14)-(5又十分之三)÷(-14)
=(8+7/10)÷(-14)-(5+3/10)÷(-14)
=[(8+7/10)-(5+3/10)]÷(-14)
=(8+7/10-5-3/10)÷(-14)
=(3+4/10)÷(-14)
=17/5÷(-14)
=-17/70
0.75+五分之一÷(-五分之四)-五分之二×(-四分之五)
=3/4+1/5÷(-4/5)-2/5×(-5/4)
=3/4+1/5×(-5/4)-2/5×(-5/4)
=3/4+(1/5-2/5)×(-5/4)
=3/4+(-1/5)×(-5/4)
=3/4+1/4
=1