(1/6+1/4)*9 как там решить

(1/6+1/4)*9=3 3/4 1) 1/6+1/4=(1*2)/12+(1*3)/12=(2+3)/12=5/12 2) 5/12*9=5/12*9/1=5/4*3/1=15/4=3 3/4