Tenth: 243.9
Hundredth: 243.88
Ten: 240
Hundred: 200
Answers:
The next two terms are 67.5 and 101.25 in that order.
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Explanation:
Divide the second term over the first to get 30/20 = 1.5
Divide the third term over the second term to get 45/30 = 1.5
The common ratio is 1.5, which means we multiply 1.5 by each term to get the next term
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fourth term = 1.5*(third term) = 1.5*45 = 67.5
fifth term = 1.5*(fourth term) = 1.5*67.5 = 101.25
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As a shortcut you can plug n = 4 and n = 5 into the function t(n) = 20*(1.5)^(n-1) to get the fourth and fifth terms respectively.
Subtract 8d from both sides
21 = 12d + 5 - 8d
Simplify 12d + 5 - 8d to 4d + 5
21 = 4d + 5
Subtract 5 from both sides
21 - 5 = 4d
Simplify 21 - 5 to 16
16 = 4d
Divide both side by 4
16/4 = d
Simplify 16/4 to 4
4 = d
Switch sides
d = 4
<u>Check answer</u>
8d + 21 =12d + 5
Let d = 4
8 × 4 + 21 = 12 × 4 + 5
Simplify 8 × 4 to 32
32 + 21 = 12 × 4 + 5
Simplify 12 × 4 to 48
32 + 21 = 48 + 5
Simplify 32 + 21 to 53
53 = 48 + 5
Simplify 48 + 5 to 53
53 = 53
J -60
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