What is the value of x in the equation 3x + 5 = 20?

To find the value of x in the equation 3x + 5 = 20, we should isolate x. Begin by subtracting 5 from both sides of the equation to eliminate the constant term on the left side:

3x + 5 - 5 = 20 - 5

This simplifies to:

3x = 15

Next, divide both sides by 3 to solve for x:

3x / 3 = 15 / 3

This further simplifies to:

x = 5

Thus, the value of x is 5. This approach, which involves reversing the order of operations by first addressing the addition (or subtraction) followed by multiplication (or division), is essential when solving linear equations. The calculated value aligns with the structure of the original equation, satisfying the condition that when you substitute x back into the equation, the left-hand side equals the right-hand side.