From cosine law
c^2 = a^2 + b^2 -2abcos(C)
cos(C) = (a^2 + b^2 - c^2)/2ab
this formula will solve your problem
Answer: DECAY
Step-by-step explanation:
(.85) is less than 1
Lets Anna's age = A
Mr. Goldstein age = G
Mr. Goldstein is 4 times as old as his daughter Anna.
So G= 4A
In 4 years, he will be 3 times as old as Anna
we add 4 with Both their ages
G + 4 = three times of A + 4
G + 4= 3(A + 4)
We know G= 4A, replace it in above equation
4A + 4= 3(A + 4)
4A + 4= 3A + 12
Subtract 3A from both sides
A + 4 = 12
Subtract 4 from both sides
A = 8
So Anna's age = 8 years
Answer:
Equations::
4c + 8t = 58
2c + 3t = 23
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Modify for elimination:
4c (4c*1) + 8t (8t*1)= 58
4c (2c*2) + 6t (3t*2)= 46
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Subtract and solve for "t":
2t (8t-6t) = 12
t = $6 (cost of one table)
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Solve for "c":
2c + 3t = 23
2c + 18 = 23
2c = 5
c = $2.50 (cost of one chair)
-1000 is the answer to 5*10^-3
