Question

rezolvati ecuatiile a) x patrat =144,x apartine R+ b) 2y patrat =200,y apartine R- c) (z-1) patrat -25=0, z apartine R-
d) x la a patra =4, x apartine R

Answer 1

a)   x²=144
x=√144
x=+-12
x=12  deoarece x∈R+
b)  2y²=200
y²=200÷2
y²=100
y=√100
y=+-10
y= - 10   deoarece x∈R-
c)   (z-1)² -25 =0
(z-1)²=25
(z-1)=√25
(z-1)=+-5
z=-5+1
z=-4   deoarece z∈R-
d)  x la a patra =4
x²=√4
x²=2
x=+-√2

Answer 2

a)x²-144=0
(x-12)(x+12)=0
x1=12;x2=-12∉R+

 d)(x²-2)(x²+2)=0
(x-√2)(x+√2)(x²+2)=0
x1=√2
x2=-√2
x3, 4∈C\R


b)2y²=100 y∈R-
y²=100
y=-10


c)(z-1)²=25
z-1=-5
z=-4