Answer:
x=3 or x=−17
Explanation:
Let's solve your equation step-by-step.
x2+14x−51=0
Step 1: Add 51 to both sides.
x2+14x−51+51=0+51
x2+14x=51
Step 2: The coefficient of 14x is 14. Let b=14.
Then we need to add (b/2)^2=49 to both sides to complete the square.
Add 49 to both sides.
x2+14x+49=51+49
x2+14x+49=100
Step 3: Factor left side.
(x+7)2=100
Step 4: Take square root.
x+7=±√100
Step 5: Add -7 to both sides.
x+7+−7=−7±√100
x=−7±√100
x=−7+10 or x=−7−10
x=3 or x=−17