Answer:
[tex]40y^4[/tex]
Step-by-step explanation:
To find the least common multiple (lcm) of a pair of numbers, we can multiple the numbers together and divide by the greatest common factor of those numbers. The greatest common factor (gcm) of [tex]8y^3[/tex] and [tex]10y^4[/tex] is [tex]2y^3[/tex], so
[tex]lcm(8y^3, 10y^4)=\frac{8y^3\cdot10y^4}{2y^3} =4\cdot10y^4=40y^4[/tex]