Answer:
1. Equation
2. Expression
3. Equation
4. Equation
Step-by-step explanation:
To decide whether the given problems are an equation or an expression.
An equation is of the form:
LHS (Left Hand Side) expression = RHS(Right Hand Side) expression
Let us have a look at each problem one by one:
1. A number decreased by 3 is 7.
Let the number be
As per the given statement:
![x - 3 =7](https://tex.z-dn.net/?f=x%20-%203%20%3D7)
Therefore, is an equation.
2. 9+n the product of a number and eleven.
Let the number be
As per the given statement:
![9+n(x\times 11)](https://tex.z-dn.net/?f=9%2Bn%28x%5Ctimes%2011%29)
No equal to sign, so it is an expression.
3. The quotient of a number and 6 is 2.
Let the number be
As per the given statement:
![\dfrac{x}6 = 2](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%7D6%20%3D%202)
Therefore, it is an equation.
4. ![x-5=21](https://tex.z-dn.net/?f=x-5%3D21)
Therefore, it is an equation.