Answer :
To solve the expression [tex]\(-3b^2 + 25\)[/tex] when the value of [tex]\(b\)[/tex] is 7, follow these steps:
1. Substitute the value of [tex]\(b\)[/tex] in the expression:
[tex]\(-3 \times (7)^2 + 25\)[/tex].
2. Calculate [tex]\(b^2\)[/tex], which is [tex]\(7^2\)[/tex]:
[tex]\[
7^2 = 49
\][/tex]
3. Multiply the square of [tex]\(b\)[/tex] by [tex]\(-3\)[/tex]:
[tex]\[
-3 \times 49 = -147
\][/tex]
4. Add 25 to the result of the multiplication:
[tex]\[
-147 + 25 = -122
\][/tex]
So, the value of the expression when [tex]\(b = 7\)[/tex] is [tex]\(-122\)[/tex].
Therefore, the correct answer is D. -122.
1. Substitute the value of [tex]\(b\)[/tex] in the expression:
[tex]\(-3 \times (7)^2 + 25\)[/tex].
2. Calculate [tex]\(b^2\)[/tex], which is [tex]\(7^2\)[/tex]:
[tex]\[
7^2 = 49
\][/tex]
3. Multiply the square of [tex]\(b\)[/tex] by [tex]\(-3\)[/tex]:
[tex]\[
-3 \times 49 = -147
\][/tex]
4. Add 25 to the result of the multiplication:
[tex]\[
-147 + 25 = -122
\][/tex]
So, the value of the expression when [tex]\(b = 7\)[/tex] is [tex]\(-122\)[/tex].
Therefore, the correct answer is D. -122.
