College

If the value of [tex]$b$[/tex] is 7, then what is the value of the expression [tex]-3b^2 + 25[/tex]?

A. -122
B. 122
C. 17
D. 172

Answer :

To find the value of the expression [tex]\(-3b^2 + 25\)[/tex] when [tex]\(b = 7\)[/tex], follow these steps:

1. Substitute the value of [tex]\(b\)[/tex]:
Replace [tex]\(b\)[/tex] with 7 in the expression:
[tex]\[
-3 \times (7)^2 + 25
\][/tex]

2. Calculate [tex]\(b^2\)[/tex]:
Compute [tex]\(7^2\)[/tex], which is:
[tex]\[
7 \times 7 = 49
\][/tex]

3. Multiply by [tex]\(-3\)[/tex]:
Now, multiply 49 by [tex]\(-3\)[/tex]:
[tex]\[
-3 \times 49 = -147
\][/tex]

4. Add 25 to the result:
Add 25 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 A. -122.