Find the roots of the quadratic equation

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers

Solve x+3y=6 and 4x-6y=6 by elimination . show work !