حل السؤال 21، 4MA1/1H يونيو 2021: الكسور الجبرية

1. 1Substitute y = 5/(5a − 2) into x = 5/(9y + 5)
2. 29y = 45/(5a − 2), so the bottom is 45/(5a − 2) + 5
3. 3Write it over one denominator: (45 + 5(5a − 2))/(5a − 2)
4. 445 + 25a − 10 = 35 + 25a, so the bottom is (35 + 25a)/(5a − 2)
5. 5Dividing by a fraction turns it over: x = 5(5a − 2)/(35 + 25a)
6. 635 + 25a = 5(7 + 5a), so the 5s cancel
7. 7x = (5a − 2)/(7 + 5a)

Answer(5a − 2)/(7 + 5a)