Question

zad.1 Wyznacz a , którego prosta jest rownolegla k: (a+1)x+2y+3=0 do prostej l: y-2x=0

prosze o szybka odpowiedz!

Answer 1

(a+1)x+2y+3=0     ||     y-2x=0

2y = -(a+1)x - 3              y = 2x

y = -(a+1)/2 x - 3/2  ||   y = 2x  ⇔   -(a+1)/2 = 2  

                                                  -(a+1) = 4

                                                  -a - 1 = 4

                                                  -a = 4 + 1

                                                 -a = 5

                                                  a = -5  ------------  odpowiedź