the sum of two numbers is 15 less than twice the first number their difference is 5 less than twice the second number. Find the number

+2

(2) Answers

roxxi

[latex]2n-15=5-2n[/latex]
[latex]4n=20[/latex]
[latex]\frac{4n}{4}=\frac{20}{4}[/latex]
[latex]n=5[/latex]
The number is 5

Polieke

x --- first number
y --- second number
x + y = 2x - 15
x - y = 2y - 5
x - 2x + y = -15
x - y - 2y = - 5
-x + y = -15
x - 3y = - 5
-----------------
-2y = -20 /:(-2)
y = 10
x - 3y = - 5 ⇒ x = - 5 + 3y = - 5 + 3 · 10 = - 5 + 30 = 25
Ans.:
x = 25
y = 10