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3 years ago

10

Marie has $830 in her bank account and withdraws $60 each month. Denise has $970 in her bank account and withdraws $80 each mont

h.
In how many months will Marie and Denise have equal amounts of money in their accounts?
A. 4
B. 5
C. 7
D. 9

1 answer:

Phantasy [73]3 years ago

7 0

830-60x=970-80x
-60x=140-80x
20x=140
2x=14
x=7

C, 7 months

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Answer:

x = 3 + √6 ; x = 3 - √6 ; $x = \frac{2+3\sqrt{2}}{2}$ ; $x = \frac{2-(3)\sqrt{2}}{2}$

Step-by-step explanation:

Relation given in the question:

(x² − 6x +3)(2x² − 4x − 7) = 0

Now,

for the above relation to be true the following condition must be followed:

Either (x² − 6x +3) = 0 ............(1)

or

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now considering the equation (1)

(x² − 6x +3) = 0

the roots can be found out as:

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the roots are

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or

$x = \frac{6\pm\sqrt{36-12}}{2}$

or

$x = \frac{6+\sqrt{24}}{2}$ and, x = $x = \frac{6-\sqrt{24}}{2}$

or

$x = \frac{6+2\sqrt{6}}{2}$ and, x = $x = \frac{6-2\sqrt{6}}{2}$

or

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we have

the roots are

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or

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or

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Hence, the possible roots are

x = 3 + √6 ; x = 3 - √6 ; $x = \frac{2+3\sqrt{2}}{2}$ ; $x = \frac{2-(3)\sqrt{2}}{2}$

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3 years ago

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Step-by-step explanation:

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