Answer:
His original farm was 333 1/3 acres
He has 66 2/3 acres of his land left
Explanation:
Lex
His total farmland = x
1/2 of x = Mr frost
100 acres = Mr slate
Remaining = 1/5x
His total farmland = Mr Frost + Mr slate + remaining farmland
x = 1/2x + 100 + 1/5x
x = 5x+2x/10 + 100
x = 7/10x + 100
x - 7/10x = 100
10x-7x/10 =100
3/10x = 100
Divide both sides by 3/10
x = 100 ÷ 3/10
= 100 × 10/3
= 1,000/3
= 333 1/3 acres
His original farm was 333 1/3 acres
He has 1/5 of his original farm
1/5 × 1000/3
= 1,000 / 15
= 66 10/15
= 66 2/3 acres
He has 66 2/3 acres of his land left