Which of these variables control the parabola's direction and width? And how does it control it? F(x): ax^2+bx+c

The gades foundation and hbm corporation are eager to donate generously to their favorite charities. the gades foundation donated $250 in the first month, and each month afterward their cumulative donation total increases by 100$ the hbm corporation donated $64, in the first month, and each month afterward their cumulative donation total increases by 75%. in which month will the hbm corporation's cumulative donation total first exceed the gades foundations' cumulative donation total?

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

Can some one me with these questions