Question

Se considera functiile f,g : R ----> R, f(x)= -3x+4, g(x)=x/3 +1
a) Determinatu coordonatele punctului de intersectie a graficelor celor 2 functii
b) Rezolvati ecuatia 3f(x) + g(4x-1)=8

Answer 1

a) -3x+4=x/3+1
-9x+12=x+3
9=10x => x=9/10

f(9/10) = -3*9/10 + 4 = (-27+40)/10= 13/10

=> pct-ul de intersectie: (9/10,13/10)

b) -9x+12+(4x-1)/3+1=8
-27x+36+4x-1+3=24
-23x=24-36+1-3
-23x=-14
=> x=14/23