👤

a) 2x-7y+3y+4x-7y
b) -2,5a + 3 1/2a^{2}+a-a^{2)-0,5a
c) {1}{2} ab - 3/4a2 + 3 3/4 ab-1,5a2+ 5/8 a2
d) 1,2a- -2/3a2+ 0,75 - 1 3/8a- 1/2 + 2/9a2