Question

What is the value of the expression below when a is 3, b is 25, and c is 5?

12
(3a + 4b + c) – (c2 + 5a)
17
32
74
97

Answer 1

To find the value of the expression \( 12 \times (3a + 4b + c) - (c^2 + 5a) \) when \( a = 3 \), \( b = 25 \), and \( c = 5 \), we can substitute the values of \( a \), \( b \), and \( c \) into the expression.

1. Substitute the values:
\[
12 \times (3 \times 3 + 4 \times 25 + 5) - (5^2 + 5 \times 3)
\]

2. Calculate \( 3a + 4b + c \):
\[
3 \times 3 = 9
\]
\[
4 \times 25 = 100
\]
\[
c = 5
\]
\[
3a + 4b + c = 9 + 100 + 5 = 114
\]

3. Calculate \( c^2 + 5a \):
\[
c^2 = 5^2 = 25
\]
\[
5a = 5 \times 3 = 15
\]
\[
c^2 + 5a = 25 + 15 = 40
\]

4. Now substitute these sums back into the main expression:
\[
12 \times 114 - 40
\]

5. Calculate \( 12 \times 114 \):
\[
12 \times 114 = 1368
\]

6. Finally, subtract \( 40 \):
\[
1368 - 40 = 1328
\]

Thus, the value of the expression is \( 1328 \).