Add the product of 7 and 10 to 80

Which expression calculates the speed in meters per second of an object that travels a distance of 100 m every 20 seconds

What is the size of the matrix resulting from

Two farmers pay a total rent of $140 for a pasture. the first farmer placed $4 oxen in the pasture, and the second farmer placed $30 sheep in the pasture. the farmers split the rent based on the proportion of the pasture eaten by their own animals that month. how much should the first farmer pay, if 1 ox eats as much as 10 sheep in a month?