Factor.x, squared, plus, 3, x, minus, 28x 2 +3x−28

The expression you provided seems to have a typo. I believe you meant to write "x^2 + 3x - 28". Here's how to factor it:

1. Write down the expression: x^2 + 3x - 28
2. Look for two numbers that multiply to -28 (the constant term) and add to 3 (the coefficient of the x term). The numbers that fit this are 7 and -4 because 7*-4 = -28 and 7 + -4 = 3.
3. Rewrite the middle term of the expression as the sum of the terms 7x and -4x: x^2 + 7x - 4x - 28
4. Group the terms to prepare for factoring by grouping: (x^2 + 7x) - (4x + 28)
5. Factor out the greatest common factor from each group: x(x + 7) - 4(x + 7)
6. Notice that the expressions in parentheses are the same. Factor out the common binomial: (x - 4)(x + 7)

So, the factored form of the expression x^2 + 3x - 28 is (x - 4)(x + 7).