Question

como se resolve a equação x/x+y=3/5
x-y=1

Answer 1

$\left \{ {{\frac{x}{x+y}=\frac{3}{5}} \atop {x-y=1}} \right. \\\\x-y=1\\x=1+y\\\frac{1+y}{1+y+y}=\frac{3}{5}\\5+5y=3+6y\\5y-6y=3-5\\-y=-2\\\\\boxed{y=2}\\\\x-2=1\\x=1+2\\\\\boxed{x=3}$