Question 256936
$11.50 = 3 dog bowls + 4 bones
$13 = 2 dog bowls + 8 bones 
11.50=3d+4b multiply this equation by -2 & add.
13=2d+8b
-23=-6d-8b
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-10=-4d
-4d=-10
d=-10/-4
d=$2.50 the price of one dog bowl.
11.50=3*2.50+4b
11.50=7.50+4b
4b=11.50-7.50
4b=4
b=$1 the price of one bone.
4d+2b=4*2.50+2*1=10+2=$12 for 4 dog bowls plus 2 bones.