Sarah was explaining her first step in factoring, but made an error in her explanation.

Question

Sarah was explaining her first step in factoring, but made an error in her explanation.

Factor: 5x^2-4x-9
Sarah said, "I know a=5, b=-4, and c=-9. Now, I need to find the factor of -9 that add to -4." What was the error in her thought process.

Answer 1

Sarah's error was that she was trying to find the factors of -9 that add to -4, when she should have been trying to find the factors of 5x^2-4x-9 that add to -4.

Sarah was explaining her first step in​ factoring, but made an error in her explanation.

Sarah's error was that she was trying to find the factors of -9 that add to -4, when she should have been trying to find the factors of 5x^2-4x-9 that add to -4.

Sarah was explaining her first step in factoring, but made an error in her explanation.