Solutions+For+Solving+By+Substitution

​​​ Example 1: {y=2x {y=x+5

**Step** ** 1. Substitute 2x in for the in the second equation. ** = 2x= x+5= =Step 2. Solve for x and substitute x from both sides.= **2x = ** **x + 5 ** -x -x X = 5  **Step 3. Substitute 5 in for x in the first equation. y = 2( 5 )** (5,10)
 * y = 10 **
 * Step 4.** **Write the solutions as an ordered pair.**
 * x = 5 y = 10 **

Example 2: {2x+y=5 {y=x-4

**Step 1.** **Substitute x-4 in for the y in the 1st equation**. Step 2.** **Simplify.** 3x- 4 = 5 ** +4 +4 3x = 9 **Step 4. Divide both sides by 3.**
 * 2x+( x-4 )=5
 * 3x- 4= 5**
 * Step 3. Solve for x and add 4 to both sides.

3x 9 -- = -- 3 3 x = 3

**Step 5. Substitute 3 in for x in the second equation.** **y = -1** **Step 6. Write the solutions as an ordered pair.** **(3, -1)**
 * y = 3 - 4**
 * x = 3 y = -1 **