Question

Vă rog să mă ajuați la 7,8 și 9

Answer 1

7. a) impart ecuatia cu 17 => x²=0 => x=0
b) x=0
c) x=0
d) 9(x²+1) =9 |:9
x²+1=1 => x=0
e) 3(x²-4) = -12 |:3
x²-4=-4 => x=0
f) x²-4+4 = 0 => x=0
8. a) 3x(x-2)=0
3x=0 => x=0
x-2=0 => x=2
b) -2x(x+2)=0
-2x=0 => x=0
x+2=0 => x=-2
c) x(x-7)=0
x=0
x-7=0 => x=7
d) x(10x-1)=0
x=0
10x-1=0 => x=1/10
e) x(4x-9)=0
x=0
4x-9=0
x=9/4
f) -7x(x-2)=0
-7x=0 => x=0
x-2=0 => x=2
g) 2x(7x-1)=0
2x=0 => x=0
7x-1=0 => x=1/7
h) x(√3x-3)=0
x=0
√3x-3=0 => x=3/√3=√3
i) x(2x-√2)=0
x=0
2x-√2=0 => 2x=√2 => x=√2/2
9. a) x²=4 => x=+/-2
b) -3x²=-75 => x²=25 => x=+/-5
c) 9x²=1 => x²=1/9 => x=+/- 1/3
d) -4x²=-100 => x²=25 => x=+/-5
e) 7x²=-7 => x²=-1 => x nu apartine lui lR
f) x²=-25 => x nu apartine lui lR
g) 100x²=36 |:4 => 25x²=9 => x²=9/25 => x=+/- 3/5
h) 8x²=-32 => x²=-4 => x nu apartine lui lR
i) x²=-49 => x nu apartine lui lR