Please solve by hand without excel, need to know the process of solving

5. A company must pay a liability of L due one year from now and 2L due two years from now. The company exactly (absolutely) matches the liabilities by buying a one-year bond with a face value of $800 and a two-year bond with face value of $2,000. Both bonds have annual coupons with a coupon rate of r for the one-year bond and 1.25r for the two-year bond. Determine r