Answer :
We start with the expression
[tex]$$
-3b^2 + 25,
$$[/tex]
and we are given that [tex]$b = 7$[/tex].
Step 1: Compute [tex]$b^2$[/tex]
When [tex]$b = 7$[/tex], we have
[tex]$$
b^2 = 7^2 = 49.
$$[/tex]
Step 2: Substitute [tex]$b^2$[/tex] into the expression
Substituting [tex]$b^2 = 49$[/tex] into the expression gives
[tex]$$
-3 \times 49 + 25.
$$[/tex]
Step 3: Multiply
Calculate the multiplication:
[tex]$$
-3 \times 49 = -147.
$$[/tex]
Step 4: Add
Now, add [tex]$25$[/tex] to [tex]$-147$[/tex]:
[tex]$$
-147 + 25 = -122.
$$[/tex]
Therefore, the value of the expression when [tex]$b = 7$[/tex] is
[tex]$$
-122.
$$[/tex]
The correct answer is [tex]$\boxed{-122}$[/tex].
[tex]$$
-3b^2 + 25,
$$[/tex]
and we are given that [tex]$b = 7$[/tex].
Step 1: Compute [tex]$b^2$[/tex]
When [tex]$b = 7$[/tex], we have
[tex]$$
b^2 = 7^2 = 49.
$$[/tex]
Step 2: Substitute [tex]$b^2$[/tex] into the expression
Substituting [tex]$b^2 = 49$[/tex] into the expression gives
[tex]$$
-3 \times 49 + 25.
$$[/tex]
Step 3: Multiply
Calculate the multiplication:
[tex]$$
-3 \times 49 = -147.
$$[/tex]
Step 4: Add
Now, add [tex]$25$[/tex] to [tex]$-147$[/tex]:
[tex]$$
-147 + 25 = -122.
$$[/tex]
Therefore, the value of the expression when [tex]$b = 7$[/tex] is
[tex]$$
-122.
$$[/tex]
The correct answer is [tex]$\boxed{-122}$[/tex].
