Question

A farmer plants corn and wheat on an 180-acre farm.The farmer wants to plant three times as many acres of corn as wheat.How many acres of each crop should the farmer plant?

Answer 1

let x be the number of acres of corn
let y be the number of acres of wheat

corn and wheat will take up 180 acres
x+y=180

3 times corn than wheat
x=3y

2 equations 2 unknown
x+y=180
x=3y

solving using substitution
x+y=180

substitute for x
x+y=180
(3y)+y=180
3y+y=180
4y=180

divide by 4 to both sides
4/4 y = 180/4
y=45

45 acres of wheat planted

using 2nd equation to find x
x=3y
x=3(45)
x=135

135 acres of corn planted