# Secondary 2 Maths

## 1 Answer

\[500=(5x-5y)^2=(5x)^2+(5y)^2 -2\cdot (5 x)(5y)=25x^2+25y^2-50xy.\]

Since $xy=5$,

\[500=25x^2+25y^2-50xy=25x^2+25y^2-50\cdot 5=25x^2+25y^2-250\]

\[\Rightarrow 500+250=25x^2+25y^2\]

\[\Rightarrow 750=25(x^2+y^2)\]

\[\Rightarrow x^2+y^2=\frac{750}{25}=30.\]

Savionf

537

Join Matchmaticians Affiliate Marketing
Program to earn up to 50% commission on every question your affiliated users ask or answer.

- 1 Answer
- 151 views
- Pro Bono

### Related Questions

- Algebra Word Problem #2
- Closest Points on Two Lines: How to use algebra on equations to isolate unknowns?
- Donald is 6 years older than Sophia. In 4 years the sum of their ages will be 74. How old is Donald now?
- Algebra Word Problem 2
- College Algebra Help
- Induced and restricted representation
- Stuck on this and need the answer for this problem at 6. Thanks
- Use first set of data to derive a second set