Question

rezolvati in R exercitiile : VA ROG AM NEVOIE IN 5 MINUTE TRB SA MERG LA SCOALA

Answer 1

a) (2x+3)²-(x+2)(x-2) = 3x²+8x+1
4x²+12x+9-(x²+4) = 3x²+8x+1
4x²+12x+9-x²-4 = 3x²+8x+1
3x²+12x+5 = 3x²+8x+1
3x²+12x+5-3x²-8x-1 = 0
4x+4 = 0
4x = -4
x = -4/4
x = -1.

b) (2x+1)²+(2x-3)² = (3x-1)²-x²+3
4x²+4x+1+4x²-12x+9 = 9x²-6x+1-x²+3
8x²-8x+10 = 8x²-6x+4
8x²-8x+10-8x²-6x-4 = 0
-14x+6 = 0
-14x = -6
x = -6/-14
x = 3/7.

c) (x+1)²-(x-1)² = (2x+1)²-4x²
x²+2x+1-(x²-2x+1) = 4x²+4x+1-4x²
x²+2x+1-x²+2x-1 = 4x+1
4x = 4x+1
0 = 1 (F).


d) (x+1)²+(x+2)²+(x+3)²+(x+4)² = (2x+4)²
x²+2x+1+x²+4x+4+x²+6x+9+x²+8x+16 = 4x²+16x+16
4x²+20x+30 = 4x²+16x+16
4x²+20x+30-4x²-16x-16 = 0
4x+24 = 0
4x = -14
x = -14/4
x = -7/2.



J'espère aidé :)