Question

A farmer is going to plant more than 50 acres in corn this year.

If a represents the number of acres planted in corn, write an inequality to describe all possible values of a.


a>50A is greater than 50

a<50a<50

a≥50A is greater than or equal to 50

a≤50

Answer 1

+ 1) is an even number.

Take any n ∈ N, then n is either even or odd.

• Suppose n is even ⇒ n = 2m for some m ⇒ n(n + 1) = 2m(n + 1) ⇒ n(n + 1) is even.

• Suppose n is odd ⇒ n+ 1 is even ⇒ n+ 1 = 2m for some m ⇒ n(n+ 1) = 2nm ⇒ n(n+ 1)

is even. QED

2. The sum of the first n natural num

Explanation:

a>50A is greater than 50

a<50a<50

a≥50A is greater than or equal to 50

a≤50

Answer 2

• A. a > 50

Explanation:

If a is the number of acres, and the farmer is going to plant more than 50 acres, then the correct inequality is:

• a > 50