Find the value of the expression $ {a^2} + 2{b^2} - 3{c^2}$ ; when a = 3, b = 0, c = 2.

Hint: This is a simple question in which we only calculate the value of a given expression by simply putting the values given in the question. So, let’s how we can solve this question.

Complete step-by-step answer:
Given,
a = 3, b = 0 and c = 2
And we have given expression $ {a^2} + 2{b^2} - 3{c^2}$
We simply put the values of a, b and c in the above expression to get the value of the given expression.
$ \Rightarrow $ $ {a^2} + 2{b^2} - 3{c^2}$
$ \Rightarrow $ $ {(3)^2} + 2 \times {(0)^2} - 3 \times {(2)^2}$ (putting the values of a, b, and c)
$ \Rightarrow $ 3 X 3 + 2 X 0 X 0 – 3 X 2 X 2 (splitting the values of the square)
$ \Rightarrow $ 9 + 0 – 12
$ \Rightarrow $ 9 – 12
$ \Rightarrow $ -3 (we have negative value because subtraction sign is bigger than the addition sign)

Note: This is a very simple question in which we only have to put the values in the given expression. If we have given the value of a, b and c then the question says to solve the given expression then first we will always put the values of the given a, b and c. After that we will solve the further question.
An algebraic expression in mathematics is an expression which is made up of variables and constants, along with algebraic operations (addition, subtraction, etc.). Expressions are made up of terms. They are also termed as algebraic equations. For example - 5x + 2y – 7, 4x – 20, etc.
These expressions are represented with the help of unknown variables, constants and coefficient. The combination of these three (as terms) is said to be an expression.
For example – (7x – 4) this is an expression.
x is a variable; whose value is unknown to us which can take any value.
7 is known as the coefficient of x, as it is a constant value used with the variable term and is well defined.
4 is the constant value term which has a definite value.