To find the domain of the function f(x) = 7x / (x + 3), we need to consider any restrictions on the values that x can take. In this case, the only restriction is that the denominator cannot be equal to zero because division by zero is undefined.
So, to find the domain, we set the denominator x + 3 to not equal zero and solve for x:
x + 3 ≠ 0
Subtracting 3 from both sides, we get:
x ≠ -3
Therefore, the domain of the function f(x) = 7x / (x + 3) is all real numbers except -3.
In interval notation, the domain can be expressed as (-∞, -3) U (-3, +∞).