### Home > A2C > Chapter 1 > Lesson 1.1.3 > Problem 1-37

1-37.

Nissos and Chelita were arguing over a math problem. Nissos was trying to explain to Chelita that she had made a mistake in finding the

*x*-intercepts of the function

*.*

*"No*

*way!"*Chelita exclaimed.

*"I know how to find x-intercepts! You make the y equal to zero and solve for x. I know I did this right!"*Here is Chelita's work:

Step 1:

Step 2: Therefore,

*.*

Step 3: So

.

Nissos tried to explain to Chelita that she had done something wrong. What is Chelita's error?

**Justify**and explain your answer completely.

Notice that 10*x* is being subtracted, not added.

Her error was that she makes a sign error while factoring.

The correct factorization is