Question

х (х-2)=63; х (х+4)=77

Answer 1

$x^{2} -2x-63=0 \ D= b^{2} -4ac= (-2)^{2} -4*1*(-63)=256 \ x_{1} = frac{-(-2)+ sqrt{256} }{2*1} = frac{4+16}{2} =10 \ x_{2}= frac{-(-2)- sqrt{256} }{2*1} = frac{4-16}{2} =-6 \ x^{2} +4x-77=0 \ D= b^{2} -4ac= 4^{2} -4*1*(-77)=16+308=324 \ x_{1}= frac{-4+ sqrt{324}}{2*1} = 7 \ x_{2} = frac{-4- sqrt{324} }{2}=-11$