Question

show how to evaluate the equation for x=2 and x=5 without simplifying first plug in the x values then evaluate
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 \( x = 5 \), \( y = 3 \).