show how to evaluate the equation for x=2 and x=5 without simplifying first plug in the x values then evaluate

Question

y=5+3x-7-2x

Answer 1

To evaluate the equation \( y = 5 + 3x - 7 - 2x \) for \( x = 2 \) and \( x = 5 \) without simplifying first, follow these steps:

Step 1: Plug in \( x = 2 \)

1. Substitute \( x = 2 \) into the equation: \[ y = 5 + 3(2) - 7 - 2(2) \]

2. Now evaluate it step-by-step:

   • Calculate \( 3(2) = 6 \)
   • Calculate \( 2(2) = 4 \)

   Substitute these back into the equation: \[ y = 5 + 6 - 7 - 4 \]

3. Now perform the addition and subtraction:

   • First, calculate \( 5 + 6 = 11 \)
   • Then \( 11 - 7 = 4 \)
   • Finally, \( 4 - 4 = 0 \)

So when \( x = 2 \), \( y = 0 \).

Step 2: Plug in \( x = 5 \)

1. Substitute \( x = 5 \) into the equation: \[ y = 5 + 3(5) - 7 - 2(5) \]

2. Evaluate it step-by-step:

   • Calculate \( 3(5) = 15 \)
   • Calculate \( 2(5) = 10 \)

   Substitute these back into the equation: \[ y = 5 + 15 - 7 - 10 \]

3. Now perform the addition and subtraction:

   • First, calculate \( 5 + 15 = 20 \)
   • Then \( 20 - 7 = 13 \)
   • Finally, \( 13 - 10 = 3 \)

So when \( x = 5 \), \( y = 3 \).

Summary of Results

• For \( x = 2 \), \( y = 0 \).
• For \( x = 5 \), \( y = 3 \).