Question

If y=m^4=n^3 and y is greater than 1, then mn=

Answer 1

y^(1/2)
y^(1/7)
y^(7/12)
y^7
y^12

Answer 2

y=m^4 imples m=y^(1/4)
y=n^3 implies n=y^(1/3)
n*m = y^(1/3)*y^(1/4)=y^(1/3+1/4) = y^(7/12)

Answer 3

we use the fact that y is positive to take the fourth root