(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Solve each sysytem usiing any method you wish:

x^{2}-y^{2}=21

x+y=7

2. Relevant equations

x^{2}-y^{2}=21

x+y=7

3. The attempt at a solution

I chose to do the substitution method.

so i change equation 2 to this: y=7-x and substitute it into the other equation in place of y.

so now equation 1 is this x^{2}-(7-x)^{2}=21

so i foil out that part to get x^{2}-(49-14x+x^{2})=21

now this is where im stuck im not sure what to doo becuase im not sure if the - outside the paranthesis turns everything inside them to the oposite sign? or what?

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# Homework Help: System of Equations and Inequalities

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