Question

Evaluate the expression when$x=20\text{and}y=5$.

$y^2-x$

Short answer

The value of the expression is5.

Step-by-step solution

Step 1  . Order of operations

To evaluate any expression involving more than one operation, follow the below order of operations:

• First evaluate expressions inside grouping symbols like parentheses ( ) or brackets [ ].
• Evaluate the exponents.
• Perform Multiplication and division from left to right.
• Perform addition and subtraction from left to right.

Step 2  . Evaluate the exponent

To evaluate the given expression$y^2-x$, substitute 20 for x and 5 for y and simplify further as shown below

$\begin{array}{c}{y}^2-x={\left(5\right)}^2-20\\ =25-20\end{array}$

Step 3  . Subtract the numbers

Now to simplify further, subtract the numbers to get

$\begin{array}{l}25-20\\ =5\end{array}$

Thus, the value of the expression is 5.