You are at the store, and are trying to remember how much bread, meat, and cheese you were supposed to buy. The bread costs $1 per loaf, the meat costs $4 per pound, and the cheese costs $3 per pound. You know that you are to buy eight items, that the total cost will be $17, and that you are supposed to purchase three times as much cheese as meat. How many of each do you need to purchase?

Step-by-step explanation:

Let loaf of bread be b, meat be m and cheese be c

Based on the given, we have following equations:

Subtract the first equation from the third and substitute c with m:

Then

x= -8

step-by-step explanation:

  b:   ∠x = 28.6°, ∠y = 31.2°, ∠z = 120.2°

step-by-step explanation:

this is one of those questions where "test taking skill" is all you need. the only answer that has angles that sum to 180° is the one shown above. the remaining choices do not describe the angles of a triangle.

if you want to do more work than simply adding the offered numbers, you can also check them against the law of sines. it should be true that

  x/sin(x) = y/sin(y) = z/sin(z)

and all of these ratios must be greater than 15, the longest side length.

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if you want to solve the triangle from scratch, i'd suggest solving for the largest angle using the law of cosines.

  z² = x² +y² -2xy·cos(z)

  z = arccos((x² +y² -z²)/(2xy)) = arccos(-75.11/149.4) = 120.182°

now you can find y from the law of sines

  y = arcsin(y/z·sin(z)) = 31.242°