1.
[tex]x \times y = 1020 \\ ( x \ + 5) \times y = 1360 \\ xy + 5y = 1360 \\ 5y = xy + 5y - xy = 1360 - 1020 = 340 \\ y = 340 \div 5 = 68 \\ x = 1020 \div y = 15[/tex]
2.
[tex]xy = 3420 \\ (x - 6) \times y = 3150 \\ xy - 6y = 3150 \\ 3420 - 6y = 3150 \\ 6y = 3420 - 3150 = 270 \\ y = 270 \div 6 = 45 \\ x = 3420 \div y = 76[/tex]