Розділ 1. РАЦІОНАЛЬНІ ВИРАЗИ » 7.5

7.5 Спростіть вираз: 1) (m/5 + 5/m – 2) • 1/(m-5) = (m^2- 10m+25)/5m • 1/(m-5) = ((m-5)^2 • 1)/(5m • (m-5)) = (m-5)/5m; 2) (1 – x/y) : (1 + x/y) = (y-x)/y : (y+x)/y =b – 3 ((y-x) • y)/(y • (y+x)) = (y-x)/(y+x); 3) (b/(b-3) – 2b) • (b-3)/b = (b-2b^2+ 6b)/(b-3) • (b-3)/b = ((7b-2b^2 )(b-3))/(b-3)b = (b(7-2b))/b = 7 – 2b; 4) (3 – m/(m+2)) : (4m+12)/(m^2+ 2m) = (3m+6-m)/(m+2) • (m^2+ 2m)/(4m+12) = (2m+6)/(m+2) • (m^2+ 2m)/(4m+12) = (2(m+3) • m(m+2))/((m+2) • 4(m+3)) = m/2.