(Electrical Circuits Mathematics) Can someone help with the equations used to solve problems 3-4?

Find the value of 1715⋅211.though these numbers aren't quite as nice as the ones from the example or the previous part, the procedure is the same, so this is really no more difficult. give the numerator followed by the denominator, separated by a comma.

Solve the equation x/4 - 5= -8 -27 -12 -7 12

How are sas and sss used to show that two triangles are congruent?