Question 1168429
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Solve the equation

    x^2 + 2x - 15 = 0


by factoring

    (x+5)*(x-3) = 0.


The roots are  x= - 5  and  x= 3.



Since the leading coefficient at x^2 is positive ( it is 1 ),  the parabola is open up.


So, it is negative between the roots and positive outside.



Thus the answer to the problem's question is this set  -5 <= x <= 3,

or, in the interval form, the set  [-5,3].
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Answered, solved and explained.


And completed.



Is everything clear to you in my solution ?