Question 708873
These must be two stores of the same company; otherwise each store would charge different prices for an item.  


x price of ball
y price of  bag


10x+2y=155
AND
12x+3y=189


Divide the second equation by 3:
4x+y=63


Now your system is this:
{{{10x+2y=155}}}
{{{4x+y=63}}}


Subtract 2 times the second equation from the first equation and find value for x.
{{{10x+2y-8x-2y=155-126}}}
{{{2x=29}}}
{{{highlight(x=14.50)}}}, $14.50 for a soccer ball. 


Finding y:
4x+y=63
y=63-4x
{{{y=64-4(14.5)}}}
{{{highlight(y=6.00)}}}, $6.00 for a soccer bag.