Please help with this qns

9514 1404 393

  $70

Step-by-step explanation:

Four relationships are given among four unknowns. Define the following variables: p, c -- the cost of a pie and a cake, respectively. q, d -- the number of pies and cakes, respectively.

  q/d = 5/2 . . . . . the ratio of pies to cakes sold

  pq +cd = 3780 . . . . revenue from the sales

  p = c -35 . . . . . a pie is $35 less than a cake

  cd = pq -420 . . . . revenue from cakes is $420 less than for pies

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The equations are non-linear, so we're making up this process as we go along. We observe that 'pq' and 'cd' are involved in relations that give us their sum and difference, so these products are easily found. Their ratio can let us take advantage of our knowledge of q/d.

Substituting for cd in the second equation, we get ...

  pq +(pq -420) = 3780

  2pq = 4200

  pq = 2100

  cd = 2100 -420 = 1680

Now, we can write ...

  pq/cd = 2100/1680 = 5/4

  (p/c)(q/d) = 5/4 = (p/c)(5/2) . . . . substitute for q/d

  p/c = 1/2 = (c -35)/c . . . . . . . . . . substitute for p

  c = 2(c -35) . . . . multiply by 2c

  c = 70 . . . . . . . . add 70-c

The cost of a cake is $70.

Additional comment

24 cakes were sold at $70 each. 60 pies were sold at $35 each.

f(x) is   are being squared

g(x) is   increasing by 2

h(x) is adding .25 each time

k(x) is taking the square root

f(x) and k(x) are exponential functions