$\Sigma M_C = 0$

$5R_1 + 2(750) = 3000$

$R_1 = 300 \, \text{lb}$

$\Sigma M_A = 0$

$5R_2 + 3000 = 7(750)$

$R_2 = 450 \, \text{lb}$

**To draw the Shear Diagram**

- V
_{A} = R_{1} = 300 lb
- V
_{B} = V_{A} + Area in load diagram

V_{B} = 300 + 0 = 300 lb
- V
_{C} = V_{B} + Area in load diagram

V_{C} = 300 + 0 = 300 lb

V_{C2} = V_{C} + R_{2} = 300 + 450 = 750 lb
- V
_{D} = V_{C2} + Area in load diagram

V_{D} = 750 + 0 = 750

V_{D2} = V_{D} - 750 = 750 - 750 = 0

**To draw the Moment Diagram**

- M
_{A} = 0
- M
_{B} = V_{A} + Area in shear diagram

M_{B} = 0 + 300(2) = 600 lb·ft

M_{B2} = V_{B} - 3000

M_{B2} = 600 - 3000 = -2400 lb·ft
- M
_{C} = M_{B2} + Area in shear diagram

M_{C} = -2400 + 300(3) = -1500 lb·ft
- M
_{D} = M_{C} + Area in shear diagram

M_{D} = -1500 + 750(2) = 0