Quadratic equations/inequalities

Question

use a calculator to solve be quadratic equations. Round to be nearest hundredth.

-x^2 + 3x + 7 = 0

Answer 1

-x^2+3x+7=0

multiply both sides by -1

x^2-3x-7=0

use the quadratic equation

(3±√(9+28))/2

(3±√37)/2

(3±6.08276)/2

9.08276/2 and -3.08276/2

4.54138 and -1.54138

x=4.54 and x=-1.54

both are solutions but if you substitute them into the original equation you don't get exactly zero but almost zero because these are rounded off numbers; if you rounded them to much smaller places you would get much more accuracy

however, if you left the answers in radical form and substituted them into the original equation you would get exactly zero