RoseG012
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PLEASE HELP ASAP!!!!

1) My brother is 5 years older than me. My sister is 3 years younger than me. How old was I when my brother was k years old? How old will my sister be when I am n years old?

2)The sum of Lisa's age and Myra's age is 19. In 10 years, Lisa will be 5 years older than Myra. How old is each girl now?

Respuesta :

NetherFury

Answer:

1)

k - 5  = m

n - 3 = s

2)

Lisa is 17 and Myra is 12


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1) Key:

brother = b

me = m/n

sister = s

Equation:

m + 5 = b

m - 3 = s

Answer:

b - k = m

n - 3 = s

2)

L + M = 19

(L + 5) + M = 29

(L + 5 - 5) + m = 24

L + M = 24 / 2 = 12

L  = 12 + 5 = 17

M = 12

Lisa will be 17 and Myra is 12

Answer :

(1) The age of mine was, [tex]x=k-5[/tex] and The age of sister was, [tex]x=n-3[/tex]

(2) The Lisa and Myra is 12 and 7 years old girls.

Step-by-step explanation :

Part 1 :

My brother is 5 years older than me.

Let the age of mine be, x

Given : The age of brother is, k years

The equation will be:

[tex]k=x+5[/tex]

So,

The age of mine was, [tex]x=k-5[/tex]

My sister is 3 years younger than me.

Let the age of sister be, x

Given : The age of mine is, n years

The equation will be:

[tex]x=n-3[/tex]

So,

The age of sister was, [tex]x=n-3[/tex]

Part 2 :

Let the age of Lisa be, x and the age of Myra be, y

The sum of Lisa's age and Myra's age is 19. That equation will be:

[tex]x+y=19[/tex]      ..........(1)

In 10 years, Lisa will be 5 years older than Myra. That equation will be:

[tex](x+10)=5+(y+10)[/tex]      ..........(2)

[tex]x+10=5+y+10[/tex]

[tex]x-y=5[/tex]

[tex]x=5+y[/tex]       ............(3)

Using the substitution method and put the equation 3 in equation 1, we get:

[tex]x+y=19[/tex]

[tex](5+y)+y=19[/tex]

[tex]5+2y=19[/tex]

[tex]2y=14[/tex]

[tex]y=7[/tex]

Now put the value of y in equation 3, we get the value of x.

[tex]x=5+y[/tex]

[tex]x=5+7[/tex]

[tex]x=12[/tex]

Thus, the Lisa and Myra is 12 and 7 years old girls.

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