If the 3’s were exponents then... i got 50r3
how i solved:
39r3 + 11r3 + 45s3 - 5s3 - 40s3
50r3 + 40s3 - 40s3
50r3 + 0
= 50r3
Well, one cup is 8 fluid ounces. So 128/8 = 16 cups.
Answer:
2x - 5 = 7
2x -5 + 5 = 7 + 5
2x = 12
2/2x = 12/2
x = 6
Step-by-step explanation:
The goal to proving identities is to transform one side into the other. We can only pick one side to transform while the other side stays the same the entire time. The general rule of thumb is to transform the more complicated side (though there may be exceptions to this guideline).
So I'll take the left hand side and try to turn it into 
One way we can do that is through the following steps:

Since we've shown that the left hand side transforms into the right hand side, this verifies the equation is an identity.
Let c=cost of chicken and d=cost of duck; 50c+30d=550 and 44c+36d=532.
So 5c+3d=55, 11c+9d=133.
Therefore 15c+9d=165, subtracting 11c+9d=133 we get: 4c=32 so c=8.
5c+3d=40+3d=55, so 3d=15 and d=5.
Cost of chicken is $8 and cost of duck is $5.