Question

POR FAVORRRRRRRRRRRRR, PRECISO P AGORA, URGENTEMENTEEEEEEEE

Answer 1

Resposta:

2 - a) $3x^{2} - 99 = 48$

$3x^{2} = 48 + 99$

$3x^{2} = 147$

$x^{2} = \frac{147}{3}$

$x^{2} = 49$

$x =$ ±$\sqrt{49}$

$x =$ ± $7$

S = {-7, 7}

b) $7x^{2} + 41 = 888$

$7x^{2} = 888 - 41$

$7x^{2} = 847$

$x^{2} = \frac{847}{7}$

$x^{2} = 121$

$x =$ ±$\sqrt{121}$

$x =$ ± $11$

S = {-11, 11}

3 - a) $4x^{2} - 20x = 0$

$x(4x - 20) = 0$

$x' = 0$

$4x - 20 = 0$

$4x = 20$

$x = \frac{20}{4}$

$x" = 5$

S = {0, 5}

b) $8x^{2} + 72x = 0$

$x(8x + 72) = 0$

$x' = 0$

$8x + 72 = 0$

$8x = -72$

$x = \frac{-72}{8}$

$x" = -9$

S = {0, -9}