Question

Simultaneous equations
x+y=5
x squared-y squared=15​

Answer 1

Answer: x=4, y=1.

Explanation:

`\left \bigg \{ {\big{x+y=5} \atop\big {x^(2)-y^(2) =15}} \right.\\\\x+y=5\\x+y-y=5-y\\x=5-y\\\\(5-y)^(2) -y^(2) =15\\5^(2) -10y+y^(2) -y^(2)=15\\25-10y=15\\25-10y-25=15-25\\ -10y=-10\\-10y / (-10)=-10 / (-10)\\y=1\\\\x+y=5\\x+1=5\\x+1-1=5-1\\x=4`

Answer 2

(4,1)

Explanation:

easiest method is to graph each equation and look for point(s) of intersection