Question

19=-3x+1f(8) = -3x+1

Answer 1

In order to solve the expression we need to isolate the "x" variable on the left side. This is done by switching terms from one side to the other of the equation, when we do that we should invert the operation of that term. If the term is multiplying on one side it should divide on the other and if it is adding on one side it should subtract on the other.

With this in mind:

`\begin{gathered} 19\text{ = -3x + 1} \\ 3x\text{ + 19 = 1} \\ 3x\text{ = 1 - 19} \\ 3x\text{ = -18} \\ x\text{ = }(-18)/(3)\text{ = -6} \end{gathered}`

The value of x is equal to -6.

We need to now evaluate the following expression:

`f(8)\text{ = 3x + 1}`

f(8) means that we need to find the value of the function when x = 8. So we need to apply 8 to the function.

`f(8)\text{ = 3}\cdot8\text{ + 1 = 24 + 1 = 25}`

The value of f(8) is 25.