解:7/36+4/452
=791/4068+36/4068
=827/4068
7/36+4/452
=7/36+1/113
=7*113/(36*113)+1*36/(36*113)
=(7*113+36)/(36*113)
=827/(36*113)
=827/4068
7/36+4/452
=7/36+1/113
=7×113/36×113+1×36/113×36
=791/4068+36/4068
=827/4068
原式=7/36+1/113
=827/4068.
可以吗?
先通分再约分