Question

Mr. Alvarado bought a total of 20 pounds of grass seed at the nursery for $168. He paid $9 per pound for Kentucky blue grass and $6 per pound for Tall Fescue. Which system of equations can be used to find the amount x (in pounds) of Kentucky blue grass and the amount y (in pounds) of Tall Fescue Mr. Alvarado purchased?

Answer 1

K+T=20

$9K + $6T = $168

K is the Kentucky blue grass in pounds

T is the Tall fescue in pounds

Explanation:

You can start with the first equation. We don't know the exact amounts of each but we know that there was a total of 20 pounds, and there were 2 types of grass seeds, so we can get that the amount of pounds of Kentucky blue grass(K) and the pounds of Tal Fescue(T) has a sum of 20.

K + T = 20

For the second equation we know that there is a sum of $168 so we'll start with that. Then, we know he paid $9 per pound of K so $9* the value of K is the amount paid for Kentucky blue grass total. This can be represented as 9K. We do the same for T, 6T. Since the sum of the cost of $9T and $6K must be $168 we can write this as:

$9K + $6T = $168