Question

A , B , C , E poza atasata

Answer 1

a)√-3x+2=5

-3x+2=25

-3x=23

x=-23/3

b)x+√4x+1=5

√4x+1=5-x

4x+1=25-50x+x²

x²-54x+24=0

c)√4-5x=6

4-5x=36

5x=-32

x=-32/5

d)√(5-x)-√x=1

√(5-x)=√x+1

5-x=x+2√x+1

2x+2√x-4=0 /:2

x+√x-4=0

presupun că x=a²

a²+a-4=0

(a+2)(a-1)=0

a1=-2. a2=1=>x1=4;x2=1

e)x+√(2x+1)=7

2x+1=(7-x)²

2x+1=49-14x+x²

x²-16x+49=0

x1,2=8±√15

f)√x+√(4-x)=2

4-x=(2-√x)²

4-x=4-4√x+x

2x-4√x=0 /:2

√x(√x-2)=0

x1=0

√x=2

x2=4