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3 years ago

The square of Mark's age 3 years ago is 6 times the age he will be in 9 years. What is his age now?

Mathematics

2 answers:

9966 [12]3 years ago

5 0

Answer:

15.

Step-by-step explanation:

Let his age now be x years. Then:

(x - 3)^2 = 6(x + 9)

x^2 - 6x + 9 = 6x + 54

x^2 - 12x - 45 = 0

(x - 15)(x + 3) = 0

x = 15, -3

We ignore the negative so his age now is 15.

Lubov Fominskaja [6]3 years ago

3 0

Answer:

Age= 15

Step-by-step explanation:

Let a be for age at the moment

(a-3)^2 =6(a+9)

a^2-6a+9=6a+54

a^2-12a-45

(a-15)(a+3)

a=15 or a=-3

Age cannot be negative (-)

Therefore

Age =15

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Answer:

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Step-by-step explanation:

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