Question

select the statements that are true.

equations always have equal signs.
an equation doesnt contain any expressions.
this is an expression: 2x - y.
this is an equation: a = b.

Explanation:

1. Recall the definitions: An equation is a mathematical statement that shows the equality of two expressions, so it must have an equal sign. So "Equations always have equal signs" is true.
2. An equation is made up of two expressions (on either side of the equal sign), so "An equation doesn't contain any expressions" is false.
3. An expression is a combination of numbers, variables, and operations. \(2x - y\) fits this, so "This is an expression: \(2x - y\)" is true.
4. \(a = b\) has an equal sign and shows equality of two expressions (\(a\) and \(b\)), so it is an equation. "This is an equation: \(a = b\)" is true.

Answer:

• Equations always have equal signs.
• This is an expression: \(2x - y\).
• This is an equation: \(a = b\).