Вправи: 681

681. Спростіть вираз:

1) 25x + 49x – 36x = 25x + 49x – 36x = 5x + 7x – 6x = 6x;

2) 18 – 32 + 50 = 9 •2 – 16 •2 + 25•2 = 32 – 42 + 52 = 42;

3) 8a + 12 200a – 50a = 4 •2a + 12 100 •2a – 25 •2a = 42a + 12 100 2a – 25 2a = 22a + 12 • 10 • 2a – 52a = 22a + 52a – 52a = 22a;

4) 3m – p + 12m = 3m – p + 4 •3m = 3m – p + 23m = 33m – p.