Question

a) (x+1) la puterea a2a -7=(x-1) la puterea a2a +1
b) (x-2) la puterea a2a +x+4=(x-1) (x+1)
c) (2x+1) la puterea a2a - (x+1) la puterea a2a=(2x+3) (2x-3) - (x-3) la puterea a2a +3
d) (x+5) la puterea a2a -(x+3) la puterea a2a -2x+1=(x+1) la puterea a2a -(x+2) (x-2) -x
Va rog ajutati-ma cat mai repede!! Dau 45 de puncte! Rezolvati cat stiti! Daca se poate as dorii pe toate!

Answer 1

a)(x+1)²-7=(x+1)²+1⇒
x²+2x+1-7=x²-2x+3⇒
x²+2x-6-x²+2x-2=0⇒
4x-8=0⇒
x=8/4⇒x=2

b)(x-2)²+x+4=(x-1)(x+1)⇒
x²=4x+4+x+4=x²-1⇒
x²-3x+8-x²+1=0⇒
-3x+9=0⇒-3x=-9⇒x=9/3⇒x=3


c)(2x+1)²-(x+1)²=(2x+3)(2x-3)-(x-3)²+3⇒

(4x²-4x+1)-(x²+2x+1)=4x²-9-(x²-6x+9)+3⇒
4x²-4x+1-x²-2x-1=4x²-9-x²+6x-9+3⇒
3x²-6x=3x²+6x-15⇒
3x²-3x²-12x+15=0⇒
-12x+15=0⇒
x=15/12

d)(x+5)²-(x+3)²-2x+1=(x+1)²-(x+2)(x-2)-x⇒

(x²+10x+25)-(x²+6x+9)-2x+1=(x²+2x+1)-(x²-4)-x⇒
x²+10x+25-x²-6x-9-2x+1=x²+2x+1-x²+4-x=0⇒
2x+17=x+5⇔2x-x=-17+5⇒x=-12
succes!
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