X^2-3x-28=0 what are the roots

Mathematics

1 answer:

Oksi-84 [34.3K]3 years ago

8 0

Answer:

$\large\boxed{x=-4\ \vee\ x=7}$

Step-by-step explanation:

$x^2-3x-28=0\\\\x^2+4x-7x-28=0\\\\x(x+4)-7(x+4)=0\\\\(x+4)(x-7)=0\iff x+4=0\ \vee\ x-7=0\\\\x+4=0\qquad\text{subtract 4 from both sides}\\x=-4\\\\x-7=0\qquad\text{add 7 to both sides}\\x=7$

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