Write the given second order equation as its equivalent system of first order equations. u′′+4u′+6u=0 use v to represent the "velocity function", i. e. v=u′(t). use v and u for the two functions, rather than u(t) and v(t). (the latter confuses webwork. functions like sin(t) are now write the system using matrices

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!