等額本息月供=[貸款本金×月利率×（1+月利率）^還款月數(shù)]÷[（1+月利率）^還款月數(shù)－1] =70萬(wàn)×4.5%/12×（1+4.5%/12）^240/[（1+4.5%/12）^240－1] =4428.55總還款額就是4428.55×240=1062850.95利息是4428.55×240－70W=362850.95