Question

a)Solutia ecuatiei : x²-1=1
b)Solutia ecuatiei:x²+6x+9=16
c)Solutia ecuatiei:(x+2)²-4=0
d)Solutia ecuatiei:2x+3/3=9/2x-3

Answer 1

a)x²+6x-7=0
Δ=b²-4ac=6²-4*1*(-7)
Δ=36+28=64
√Δ=8
x1=(-b+√Δ)/2a=(-6+8)/2=2/2=1
x2=(-b-√Δ)/2a=(-6-8)/2a=-14/2=-7
b)(x+2)²-4=0
x²+4+4x-4=0
x²+4x=0
x(x+4)=0
x1=0
x2=-4
c)2x+3/3=9/2x-3 APLIC FORMULELE DE LA PUNCTUL a)
2x+1=9/2x-3
2x(2x+1)=9-3
4x²+2x=6
4x²+2x-6=0
Δ=2²+4*4*6=4+96=100
√Δ=10
x1=(-2+10)8=8/8=1
x2=(-2-10)/8=-12/8=-3/2