Answer :
To find j :
First you need to add 4j and 9j
7(4j + 1 + 9j )
= 7(13j + 1)
Then you have to multiply 7 by the parenthesis
7(13j + 1)
= 91j + 7
You need now to transfer 7 to the other side of the equal and 7 become the opposite
91j + 7
91j = -7
now we have to isolate the j so you need to divide by 91 the two sides
91j = -7
j = -1/13
if you want to find the answer that gives an integer, replace j with the result found and make the equation
7(4j + 1 + 9j)
7[4(-1/13) + 1 + 9(-1/13)]
7(-4/13 + 1 -9/13)
7(0)
= 0
