Question 569661
{{{(7/20)+(3/16)=x}}}
find common denom fastest is to just multiply the two denoms
20*16=320
16*7=112
20*3=60
{{{(112/320)+(60/320)=x}}} add
{{{172/320=x}}}reduce by 4  172/4=43  320/4=80
{{{43/80=x}}}