Can you help with this? Thank you!

To solve for j, cross multiply:

4 x 45 = 18 x j

180 = 18j

Divide both sides by 18:

j = 10

j=10

if you dont need an explanation dont read this:

firstly you reduce the 4/18 by 2 (basically simplifying) , which then becomes 2/9..

then you cross the 2 by 45 and 9 to j (you multiply 2x45 and 9xj=9j)

so it equals to 90=9j

then you divide both sides by 9

j=10

1) 2/5

2) zero=0/1

3) zero=0/2

4) -4/5

5) undefined=3/0