Resposta:
Olá boa tarde!
São equações do segundo grau incompletas.
1)
x² - 49 = 0
x² = 49
x = ±√49
x’ = -7 ; x” = +7
S = {-7;+7}
2)
2x² - 50 = 0
2x² = 50
x² = 50/2
x² = 25
x = ±√25
x’ = -5 ; x” = +5
S = {-5;+5}
3)
x² - 1= 0
x² = 1
x = ±√1
x’ = -1 ; x” = +1
S = {-1;+1}
4)
8x² - 8 = 0
8x² = 8
x² = 8/8
x² = 1
x = ±√1
x’ = -1
x” = 1
S= {-1;+1}
5)
7x² +2 = 30
7x² = 30 – 2
7x² = 28
x² = 28 / 7
x² = 4
x = ±√4
x’ = -2 ; x” = +2
S = {-2;+2}
6)
3x² +5x = 0
x(3x +5) = 0
x = 0
3x + 5 = 0
3x = -5
x = -5/3
x’ = 0 ; x” = -5/3
S = {0;-5/3}
7)
x² -5x = 0
x(x -5) = 0
x = 0
x - 5 = 0
x = +5
x’ = 0 ; x” = +5
S = {0;+5}
8)
4x² - 12x = 0
x(4x -12) = 0
x = 0
4x -12 = 0
4x = 12
x = +3
x’ = 0 ; x” = +3
S = {0;+3}
9)
7x² + 14x = 0
x(7x +14) = 0
x = 0
7x + 14 = 0
7x = -14
x = -14/7
x = -2
x’ = 0 ; x” = -2
S = {0;-2}
10)
-2x² +10x = 0
x(-2x +10) = 0
x = 0
-2x + 10 = 0
-2x = -10 *(-1)
2x = 10
x = 10/2
x = 5
x’ = 0 ; x” = +5
S = {0;+5}
