Question

Să se rezolve ecuațiile.

Answer 1

a)x=3x-1
x=1/2

b)x²-8x=9
x²-8x-9=0
Δ=100
√Δ=10
x₁=9
x₂=-1

c)x²-4x+2=x-2
x²-4x+2-x+2=0
x²-5x+4=0
Δ=9
√Δ=3
x₁=4
x₂=1

d)2/x-1=x
x²-x-2=0
Δ=9
√Δ=3
x₁=2
x₂=-1

e)1-x²=(x+8)/3
nu are solutii reale

f)x²-4x=3(2-x)
x²-x-6=0
Δ=25
√Δ=√25=5
x₁=3
x₂=-2

g)(2x+1)²=x²+7x+61
3x²-3x-60=0
Δ=729
√Δ=27
x₁=5
x₂=-4

h)3x+5=8x+8
3x-8x=8-5
-3x=3
x=-1

i)4ˣ+3·2ˣ=2ˣ⁺²+2
2ˣ=y
y²-y-2=0
Δ=9
√Δ=√9=3
y₁=2
y₂=-1
2ˣ=y₁
2ˣ=2
x=1

j)nu are sol reale