Solve a^2 - 7a - 30 = 0

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## Re: More to come from me !! It’s been a while

The basic point in solving problems like this is the "zero product property": "if ab= 0 then either a= 0 or b= 0". Once you have that $\displaystyle (a- 10)(a+ 3)= 0$ then we must have either $\displaystyle a- 10= 0$ or $\displaystyle a+ 3= 0$. That gives, of course, two different values for a either of which satisfies the original equation.