Answer:
x = 1 ±2sqrt(5)
Step-by-step explanation:
2x^2-4x-9=29
Add 9 to each each side
2x^2-4x-9+9=29+9
2x^2-4x=38
Divide by 2
2/2x^2-4/2x=38/8
x^2 -2x =19
Complete the square
x^2 -2x + (-2/2)^2 = 19 +(-2/2)^2
x^2 -2x +1 = 19+1
(x-1)^1=2 = 20
Take the square root of each side
sqrt((x-1)^2) = ±sqrt(20)
x-1 = ±sqrt(20)
Add 1 to each side
x-1+1 = 1 ±sqrt(20)
x = 1 ±sqrt(20)
Simplifying the square root of 20
x = 1 ±sqrt(4)sqrt(5)
x = 1 ±2sqrt(5)
Answer:
D: 5 : 8 and 20 : 32
Step-by-step explanation:
A is incorrect because 3 x 1.33 = 4 and 4 x 1.25 = 5.
B is incorrect because 10 x 1.6 = 16 and 12 x 1.5 = 18.
C is incorrect because 7 x 1.428 = 10 and 10 x 1.4 = 14.
D is correct because 5 x 4 = 20 and 8 x 4 = 32.
another way of solving the ratio answers is by putting them in a fraction 5/8 = .625 and also does 20/32 = .625.....
Easy right!?
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Answer:
<u>x = -7.5 - 1.5(n−1) </u>
Step-by-step explanation:
the explicit formula for the arithmetic sequence has the form
x = a + d(n−1)
a is the first term and d is the common difference
The given arithmetic sequence is
-7.5,-9,-10.5,-12
The first term is -7.5
d = common difference = -9 - (-7.5) = -1.5
∴ x = -7.5 - 1.5(n−1)