8 Which expression is equivalent to 5(3x + 9)?

Question

a) 8x + 14
b) 45x + 15
c) 15x + 45
d) 15x - 45

Answer 1

To find the expression equivalent to \(5(3x + 9)\), we need to distribute the \(5\) across both terms inside the parentheses:

\[ 5(3x + 9) = 5 \cdot 3x + 5 \cdot 9 \]

Calculating each part, we have:

\[ 5 \cdot 3x = 15x \] \[ 5 \cdot 9 = 45 \]

Now, combine the two results:

\[ 5(3x + 9) = 15x + 45 \]

Thus, the equivalent expression is:

\[ \text{c) } 15x + 45 \]