Q4: Solve the following system of six linear equations: 2a -4b + 50 -3.50 +1.8e +4f = 52.52 -1.5a + 3b + 4c - d - 2e +5f = 21.1 5a +b-6c + 3d - 2e + 2f = -27.6 1.2a 26 + 3c + 4d -e +4 f = 9.16 4a + b - 2c - 3d - 4e +1.5 f = - 17.9 3a +b-c+4d 2e - 4f = 16.2 Q5: a. Plot the following functions using MATLAB y=a* Sin (x+b) Plot three different lines on the same plot for 1. a=b=0.125 and x(0,10) 2. a=b=0.375 and x(0,10) 3. a=b=0.5 and x(0,10) b. The initial heat distribution over a steel plate is given by the function u(x,y) = 80y2el-x20.3y2) -2.1 y 6 plot the surface u over the given range. Q6: 1.85 The Hazen Williams equation can be used to calculate the pressure drop, Pd (psi/ft of pipe) in pipes due to friction: P= 4,520(cl . 85/487) where Q is the flow rate (gpm), C is a design coefficient determined by the type of pipe, and d is pipe diameter in inches. Consider a 3.5 in. diameter steel pipe with C = 120. Calculate the pressure drop in a 1000 ft long pipe for flow rates of 250, 300, 350, 400, and 450 gpm. To carry out the calcula- tion first create a five-element vector with the values of the flow rates (250, 300, ...). Then use the vector in the formula using element-by-element oper- ations. Plot the pressure drop Pd against the volumetric flow rate