Question

Me ajudem por favor!

a)3(x² - 1 ) = 24
b)2(x² - 1) + x² + 7
c)5(x² - 1) = 4 (x² +1)
d)(x - 3) (x - 4) + 8 = x

Answer 1

a) 3$x^{2}$ - 3 = 24
3$x^{2}$ = 24 - 3
 
$\frac{3 x^{2} }{3}$ = $\frac{21}{3}$

$x^{2}$ = 7

x =$\sqrt{7}$

b) 2$x^{2}$ - 2 + 2 + 7= 3$x^{2}$ + 6

c) 5$x^{2}$ - 5 = 4$x^{2}$ + 4
  5$x^{2} - 4 x^{2}$ = 1 +1
           
  $\frac{1}{1}$ = $\frac{1}{1}$

$x^{2} = \sqrt{1}$
x = 1

d) $x^{2}$ - 4x - 3x + 12 + 8 = x
$x^{2} - 1x$ + 8 = x
$x^{2}$ + 7 = x
$x^{2} - x = -7$

x = -7