Question

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?

Answer 1

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 2

(1) The age of mine was,
`x=k-5` and The age of sister was,
`x=n-3`

(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:

`k=x+5`

So,

The age of mine was,
`x=k-5`

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:

`x=n-3`

So,

The age of sister was,
`x=n-3`

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:

`x+y=19` ..........(1)

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

`(x+10)=5+(y+10)` ..........(2)

`x+10=5+y+10`

`x-y=5`

`x=5+y` ............(3)

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

`x+y=19`

`(5+y)+y=19`

`5+2y=19`

`2y=14`

`y=7`

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

`x=5+y`

`x=5+7`

`x=12`

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