Respuesta :

ab+ac=a(b+c)
a is the shared factor

4. 36=12*3 so 12 is the shaed factor
12(1)+12(3)=12(1+3)=12(4)=48

5. 16=4*4
20=4*5
4 is shared factor
4(4)+4(5)=4(4+5)=4(9)=36