9z+z=500
10z=500
z=500/10
z=50
10k-k=702
9k=702
k=702/9
k=78
4j+5j+j=1200
10j=1200
j=1200/10
j=120
6t+3t-t=6400
8t=6400
t=6400/8
t=800
9z+z=500
10z=500
z=500/10
z=50
10k-k=702
9k=702
k=702/9
k=78
4j+5j+j=1200
10j=1200
j=1200/10
j=120
6t+3t-t=6400
8t=6400
t=6400/8
t=800