It is given here that the cost of a pair of jeans is $89. It is also given in the problem that a jeans jacket costs twice as much as the pair of jeans.
Now
The cost of the jeans jacket = (2 * 89) dollars
= 178 dollars
Cost of 1 pair of jeans = 89
So
The cost of 4 pairs of jeans = (89 * 4) dollars
= 356 dollars
So we come to know that the cost of a jean jacket is $178 and the cost of 4 pairs of jeans is $356.
Total cost for the jean jacket and 4 pairs of jeans = (178 + 356) dollars
= 534 dollars
So $534 is the total cost of the jean jacket and 4 pair of jeans.