SOLUTION: Use the quadratic formula to solve the equations: 0 = x^2 + x - 20 0 = x^2 - 5x + 6

Use the quadratic formula to solve the equations:

    



Write as







and then as







and compare to this form which you must memorize:







We see that A=1, B=1, C=-20.  and we substitute into

this formula which you must also memorize:

   

 



















Use the + for the first solution:











  That's the first solution.



Use the - for the second solution:











  That's the second solution.



There are two solutions x = 4 and x = -5.



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The other one is solved the same way.



The solutions to it are x = 3 and x = 2



Edwin