Question

If f(x)=5x-3, what is the value of f(4)

Answer 1

f(4) = 17

Explanation:

1. Know that whatever number replaces x in f(x), will replace every single x on the other side of the equal sign. Therefore, we can "plug in" 4 for x.

• 
  `f(4)=5(4)-3`
• Note: If x follows a number with no space (e.g. 5x), that means whatever value is there for x is being multiplied by the number in front of it. Therefore, in this case, x is being multiplied by 5.

2. Solve the right side of the equation.

• Multiply 5 and 4:
  `f(4)=5(4)-3=20-3`
• Subtract 20 and 3:
  `f(4)=20-3=17`
• Therefore:
  `f(4)=17`