a$)$ Prove that support$-$reaction forces are $A_y={50}^{kN}(darr)$ and $B_y={750}^{kN}(uarr).$

b$)$ Obtain the expressions for $V(x)$ and $M(x)$; then, draw the SFD and BMD$.$

c$)$ Determine the values of shear force $V_{\text{m}\text{a}\text{x}}$ and bending moment $M_{\text{m}\text{a}\text{x}}.$

$(3)$