Question

3(x-2)+5(x+1)=7
x 2+2x-3=0
x 2+x+1=0
ecuatii rapid va rog

Answer 1

$3(x-2)+5(x+1)= 7\\ 3x-6+5x+5=7\\8x-1=7\\8x=8\\x=1\\ \\ x^{2}+2x-3=0\\x^{2}+3x-x-3=0\\x(x+3)-1(x+3)=0\\(x-1)(x+3)=0\\ x= 1, x = -3 \\ S = 1 , -3\\ \\x^{2}+x+1=0\\ delta=(1)^{2}-4*(1)*(1)=1-4=-3.$
delta < 0

Nu avem solutii in R ( multimea numerelor reale)

Answer 2

Bună,

3(x-2)+5(x+1) = 7
3x-6+5x+5 = 7
8x-1 = 7
8x = 7+1
8x = 8
x = 8/8
x = 1.

x²+2x-3 = 0

a = 1
b = 2
c = -3

∆ = b²-4ac
∆ = 4+12
∆ = 16.

x1 = (-b+√∆)/2a
x1 = (-2+4)/2
x1 = 2/2
x1 = 1.

x2 = (-b-√∆)/2a
x2 = (-2-4)/2
x2 = -6/2
x2 = -3.

S = {-3;1}.


x²+x+1 = 0

a = 1
b = 1
c = 1

∆ = b²-4ac
∆ = 1-4
∆ = -3 → ∆ < 0, ecuația nu are soluții reale.



Succes!