Question

Radical din x+1= 5-x

Answer 1

Radical din (x+1) = 5-x
Se ridica la puterea a doua toata egalitatea:
x+1 = (5-x)^2
x+1 = 25-10x+x^2
x^2-11x-24 = 0
Delta = b^2-4ac =121-4*24 = 25
x1,2 = -b+sau-radical din delta/2a = 11+sau-5/2
x1 = (11+5)/2 = 8
x2 = (11-5)/2 = 3
 

Answer 2

√x+1 = 5-x
x+1=25-10x+x²
x+1-25+10x-x²=0
11x-24-x²=0
-x²+11x-24=0
x²-11x+24=0
x = -(-11)+/- √(-11)²-4*1*24/2*1
x=11+/-√121-96/2
x = 11+/-5/2
x=11+5/2 = ) x = 8
x=11-5/2 = ) x=3



√8+1=5-8
√3+1=5-3
3=-3
2=2

deci x = 3