algebra stuff

[sharp laurel]

I am stupid please help

[remote notch]

I) if two variables add up to one thing it just means in an equation form you are saying

x+y=27

Ii) x^2 - y^2 = 81

By just interpreting iy

iii) solve simultaneously for two unknowns

in I) x + y = 27, goes to y=27-x

Plug this y into Ii)

x^2 -(27-x)^2 -81= 0

Expand this expressions and solve quadratic for ur answer in x

Plug the positive/real value of x into x+y=27, solve, you now have y too

[sharp laurel]

thank you