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Two-thirds of a number is two more than one-half of another number. The sum of the number is 129. Find the numbers.​

1 Answer

3 votes

Answer: 57 ; 72

Step-by-step explanation:

Given information

2/3 of a number is 2 more than (1/2) of another number

Sum = 129

Set variables

Let x be the first number

Let y be the other number

Set system of equations


1)~(2)/(3) x=(1)/(2) y+2


2)~x + y=129

Eliminate fractions in the 1) equation


(2)/(3) x*6=(1)/(2) y*6+2*6


4x=3y+12

Move x and y onto the same side


4x-3y=12

Current System


1)~4x-3y=12


2)~x + y=129

Multiply 3 on both sides in 2) equation


x*3 + y*3=129*3


3x+3y=387

Current System


1)~4x-3y=12


2)~3x+3y=387

Add 1) equation and 2) equation together


(4x - 3y)+(3x+3y)=(12)+(387)

Expand parenthesis and combine like terms


4x - 3y + 3x + 3y = 12 + 387


4x + 3x - 3y + 3y=399


7x=399

Divide 7 on both sides


7x/7=399/7


\Large\boxed{x=57}

Substitute the x value into one of the equations to find the y value

x + y = 129

(57) + y = 129

y = 129 - 57


\Large\boxed{y=72}

Hope this helps!! :)

Please let me know if you have any questions

User Jesse
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