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Solve for 
x. Enter the solutions from least to greatest.

{:[3x^(2)-9x-12=0],[" lesser "x=◻],[" greater "x=◻]:}

Solve for x x . Enter the solutions from least to greatest.\newline3x29x12=0 lesser x= greater x= \begin{array}{l} 3 x^{2}-9 x-12=0 \\ \text { lesser } x=\square \\ \text { greater } x=\square \end{array}

Full solution

Q. Solve for x x . Enter the solutions from least to greatest.\newline3x29x12=0 lesser x= greater x= \begin{array}{l} 3 x^{2}-9 x-12=0 \\ \text { lesser } x=\square \\ \text { greater } x=\square \end{array}
  1. Identify quadratic equation: Identify the quadratic equation to solve.\newline3x29x12=03x^2 - 9x - 12 = 0\newlineWe need to find two numbers that multiply to give the product of the coefficient of x2x^2 (which is 33) and the constant term (12-12), and add up to the coefficient of xx (9-9).
  2. Find numbers that meet criteria: Find the two numbers that meet the criteria.\newlineThe numbers 12-12 and +1+1 multiply to 12-12 and add up to 11-11, which is not the coefficient we need.\newlineThe numbers 6-6 and +2+2 multiply to 12-12 and add up to 4-4, which is also not the coefficient we need.\newlineThe numbers 4-4 and +3+3 multiply to 12-12 and add up to +1+111, which is also not the coefficient we need.\newlineThe numbers +1+122 and +1+133 multiply to 12-12 and add up to +1+1, which is also not the coefficient we need.\newlineHowever, if we multiply these numbers by +1+166 (the coefficient of +1+177), we get +1+188 and +1+199, which do add up to +3+3, but we need +1+188. Therefore, we need to find another pair.\newlineThe numbers +1+122 and 4-4 multiply to +1+199 and add up to 12-1255, which is also not the coefficient we need.\newlineThe numbers +1+111 and 12-12 multiply to +1+199 and add up to 12-1299, which is also not the coefficient we need.\newlineThe correct pair of numbers that multiply to 11-1100 and add up to +1+188 are +1+122 and 12-12.
  3. Write equation with split middle term: Write the equation with the middle term split using the two numbers found.\newline3x23x12x12=03x^2 - 3x - 12x - 12 = 0\newlineGroup the terms to factor by grouping.\newline(3x23x)+(12x12)=0(3x^2 - 3x) + (-12x - 12) = 0\newlineFactor out the common factors in each group.\newline3x(x1)12(x+1)=03x(x - 1) - 12(x + 1) = 0
  4. Factor by grouping: Notice that there is a mistake in the previous step. The correct pair should be 1-1 and 12-12, which multiply to +12+12 and add up to 13-13, which is not the coefficient we need. We need to find the correct pair of numbers that multiply to 3×(12)=363 \times (-12) = -36 and add up to 9-9. The correct pair is 3-3 and 12-12.

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