Question

if x+y=13 and xy=35 find the value of x²+y²​

Answer 1

$\huge{\mathcal{\blue{\underline{Answer}}}}$

$(x + y) {}^{2} = x {}^{2} + y {}^{2} + 2xy \\ (13) {}^{2} = x {}^{2} + y {}^{2} + 2(35) \\ 169 = x {}^{2} + y {}^{2} + 70 \\ 169 - 7 0 = x {}^{2} + y {}^{2} \\ 99 = {x}^{2} + {y}^{2}$

Answer 2

\huge{\mathcal{\blue{\underline{Answer}}}}

Answer

\begin{lgathered}(x + y) {}^{2} = x {}^{2} + y {}^{2} + 2xy \\ (13) {}^{2} = x {}^{2} + y {}^{2} + 2(35) \\ 169 = x {}^{2} + y {}^{2} + 70 \\ 169 - 7 0 = x {}^{2} + y {}^{2} \\ 99 = {x}^{2} + {y}^{2}\end{lgathered}

(x+y)

2

=x

2

+y

2

+2xy

(13)

2

=x

2

+y

2

+2(35)

169=x

2

+y

2

+70

169−70=x

2

+y

2

99=x

2

+y

2