Question

PLEASE HELP

Answer 1

Answer:

Son's Age: 11

Mary's Age: 33

Step-by-step explanation:

Let set Mary and her son as variables,

M = Mary's age

S  = Mary's son age

Breakdown:

"Mary is three times as old as her son"

M = 3S

"In 12 years, Mary's age will be one less than twice her son's age"

M + 12 = 2(S + 12) - 1

we add 12 to both sides as it will be in 12 years for both

We know that M = 3S, so we plug this in

3S + 12 = 2(S + 12) - 1

Now solve for S (son's age),

3S + 12 - 12 = 2(S + 12) - 1 - 12

3S = 2(S + 12) - 13

3S = 2S + 24 - 13

3S - 2S = 2S - 2S + 24 - 13

S = 24 - 13

S = 11

To find Mary age, plug in her son age ,

M = 3S

M = 3(11)

M = 33

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