Understanding Expressions and Variables

The video explores how the value of mathematical expressions changes as variables within them change. It begins with a simple expression, 100 - x, showing that as x increases, the expression decreases. Next, it examines 5/x + 5, demonstrating that as x decreases while remaining positive, the expression increases. Finally, it analyzes 3y/2y, illustrating that the expression remains constant as y increases, provided y is non-zero.

What happens to the value of the expression 100 - x as x increases?

• It becomes undefined.

• It remains constant.

• It decreases.

• It increases.

If x is 50, what is the value of the expression 100 - x?

• 150

• 0

• 100

• 50

As x decreases while remaining positive, what happens to the expression 5/x + 5?

• It becomes zero.

• It decreases.

• It increases.

• It remains constant.

What is the value of 5/x + 5 when x is 1?

• 5

• 6

• 10

• 11

What is the value of 5/x + 5 when x is 100?

• 5.05

• 6

• 0.05

• 10

What happens to the expression 3y/2y as y increases?

• It becomes undefined.

• It increases.

• It decreases.

• It remains constant.

What is the simplified form of the expression 3y/2y?

• 1

• 0

• y

• 3/2

If y is 5, what is the value of the expression 3y/2y?

• 1

• 5

• 0

• 3/2

Why does the expression 3y/2y remain constant as y changes?

• Because it is undefined.

• Because it is always one.

• Because it is always zero.

• Because y cancels out.

What is the condition for the expression 3y/2y to remain defined?

• y must be zero.

• y must be positive.

• y must be negative.

• y must be a fraction.