Find the x-intercept(s) and the coordinates of the vertex for the parabola. Please help me! I'm so very confused.

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

Can someone answer this question? : )

Astore sells two types of radios. one type sells $87 and the other for $119. if 25 were sold and the sales were $2495, how many of the $87 radios were sold a) 5 b) 20 c) 15 d)10