a) {5 (2x-4y) +6 (-10x-15y) }:10
10x - 20y - 60x - 90y : 10
-50x - 110 y : 10
-5x - 11y
b) {(30z² - 42z) :6 + (27z +54z²) :9} ·3
{5z² - 7z + 3z + 6z²} ·3
{11z² - 4z} ·3
33z² - 12z
c)
[tex](16x^{2} +\frac{8x-40}{8} -\frac{15x^{2}+36x-147 }{3}):11\\(16x^{2} +\frac{8x-5}{1} -\frac{5x^{2}+36x-147 }{1} ):11\\(16x^{2} +8x-5-5x^{2} +36x-147):11\\(11x^{2} +44x-152):11\\x^{2} +4x-13,80[/tex]
