Question

1)daca a+b=1,2 si b=- 0,5 atunci a =...
2) calculati (1\2-4\5):(2\5)+2\7)- 1\16
3)descompuneti in factori x2+6x-4x2+20y-16

va rog..

Answer 1

1. a = 1,2 - b = 1,2 - ( -0,5) = 1,2 + 0,5 = 1,5 
2. ( 5 - 8 ) /10 : ( 14 + 10 ) / 35 - 1 /16 = 
= - 3 / 10 : 24 /35 -1 /16 = - 3 /10 · 35 / 24 - 1 /16 = 
= - 3· 35 / 10 · 24 - 1 /16 = - 105 / 240 - 1 /16 = - 7 /16 - 1 /16= 
= - 8 /16 = -1 /2