Question 773733: the sum of x+y=131. twice of one number is 5 less than other. find the number
Answer by trx1150(14)   (Show Source):
You can put this solution on YOUR website! x+y=131
Twice one number is 5 less than the other. Write an equation out of this.
2x=y-5 Now that you have two equations, use the method of substitution to solve the system.
x+y=131
2x=y-5
Let's start with the second equation first and solve for y.
2x=y-5
y=2x+5
Now we can substitute the y value into the other equation.
x+(2x+5)=131 After you substitue, solve the equation normally.
3x+5=131
3x=126
x=42
Now that we know what x equals, we can substitute its value into the other equation to solve for y.
x+y=131
(42)+y=131
y=89
x=42
y=89
The solution set is (42,89)
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