Вправи: 196

196. Виконайте дії:

1) 12a+b3a – 7b2a2 • a21b = 12a+b3a – 7b2 •aa2 •21b = 12a+b3a – b3a = 12a+b-b3a = 12a3a = 4;

2) m2- n2x2- 9 • x-3m-n – mx+3 = m-nm+n(x-3)x-3x+3(m-n) – mx+3 = m+nx+3 – mx+3 = m+n-mx+3 = nx+3;

3) a-b2a+b + 1a-b : 2a+ba2- b2 = a-b2a+b + 1 •a-b(a+b)a-b(2a+b) = a-b2a+b + a+b2a+b = a-b+a+b2a+b = 2a2a+b;

4) x – x2- xyx+y • xx-y = x – xx-y •xx+y(x-y) = x – x2x+y = x2+ xy- x2x+y = xyx+y.