Sharon is twice as old as Brian, and in 5 years the sum of their ages will be 25 years. Find their present ages.

Mathematics

1 answer:

Vinil7 [7]3 years ago

3 0

Sharon's age= 2x
Brian's age= x

(2x-5)+(x-5)= 25
3x-10=25
3x=15
x=5
Brian is 5 years old and Sharon is 10

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X+x+y+y+z+z=24

JulijaS [17]

Answer:

b = 7/2

x = 11/2

y = 21/2

z = -4

Step-by-step explanation:

2x + 2y + 2z = 24

x + y + z = 12

b + 2x + y + z = 21

2b + 2y = 28

b + y = 14

3x + y + z = 23

we can start anywhere by transforming these equations in a way that always one variable is excised by others.

so, e.g.

b = 14 - y

14 - y + 2x + y + z = 21

2x + z = 7

z = 7 - 2x

3x + y + 7 - 2x = 23

x + y = 16

16 + z = 12

z = -4

-4 = 7 - 2x

-11 = -2x

11 = 2x

x = 11/2

11/2 + y = 16

y = 16 - 11/2 = 32/2 - 11/2 = 21/2

b = 14 - 21/2 = 28/2 - 21/2 = 7/2

3 0

2 years ago

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Gnoma [55]

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