Answer:
Step-by-step explanation:
[tex]2x^2+4x-30=0\\<=> x^2+2x-15=0[/tex]
so we know that the sum of the two solutions is -2 and the multiplication -15
so we are looking for x so that
x+3=-2 and 3x=-15
it gives x = -5
another way to do it is to put (x-3) in factor as we know that 3 is one of the solutions it gives
[tex]2x^2+4x-30 = 2(x-3)(x+5)[/tex]
and then the second solution is -5
