It is simple Step 1) substitute x = 5 into the equation 3x +4 3(5) + 4 gives you 3 times 5 + 4 The answer is 15 + 4 which is 19
Now substitute a and b into the equation 3(a) + 4(b) when the a = 6 and b = 5 Hereby 3(6) + 4(5) 3 * 6 = 18 and 4* 5 = 20 18 + 20 = 38 The answer is 38
Now finally Substitute a and b Into the equation 3(3) + 4(6) 9+ 24 = 33