Problem
Solution
For this case we can do the following :
3 k + 6= 90 - (4k-7)
And then we can solve for k on this way:
3k +6 = 90 -4k +7
3k +6 = 97 -4k
7k = 97-6
7k= 91
k= 91/7= 13
then the solution for this case would be K=13
