Solve expression using pemdas and distribution
3 (x+5)

PEMDAS stand for Parentheses, Exponent, Multiplication, Division, Addition, and Subtraction.

3(x+5)

In this expression, we cannot perform any operation within the parentheses so we move to the next operation in the expression which is multiplication.

3(x+5)
becomes:
3x + 3(5)
3x + 15

We need to look for the value of x.

3x + 15 = 0
3x = -15
3x/3 = -15/3
x = -5

We need to substitute x by its value.

3(x + 5) 
3(-5 + 5)

we can perform the P in PEMDAS
3(0) = 0

multiply.
3(0) = 0
0 = 0

Rule of zero. any  number multiplied by zero is equal to zero.