Question

so if I'm multiplying right. Would it be -2*2 or -2*-2​

Answer 1

Here, we have the expression $\frac{x^2 + 4}{2}$ and we're asked

to evaluate the expression when x = -2.

To evaluate an expression, we simply plug

the value of the variable into the expression and solve.

So here, since x = -2, we have $\frac{(-2)^2 + 4}{2}$.

Notice that I used parentheses around the -2.

This is a good idea when substituting numbers in for variables.

Next, the order of operations tell us that exponent comes first.

So we have (-2)² which is 4.

So we have $\frac{4 + 4}{2}$.

Now when we have a division bar, it's important to understand

that it has the same effect on a problem as a set of parentheses

in that it groups terms together.

So this 4 + 4 can be thought of as being inside a set of parentheses.

So we can also write this as $\frac{(4 + 4)}{2}$.

Now simplify the top to get 8 and we have 8/2 which is 4.