Question

Resolva as equações de acordo com o 2 caso :

A) x² - 7x = 0
B) X²+5x=0
C) 4x²-12x=0
D)2x²=7x
E) 2x²=8x
F) -2x²+10x=0
E) 6x-10x=0​

Answer 1

Explicação passo-a-passo:

$a) \: \: \: {x}^{2} - 7x = 0 \\ x \times (x - 7) = 0 \\ ou \\ x - 7 = 0 \\ x = 7 \\ \\ \\ b) \: \: \: {x}^{2} + 5x = 0 \\ x \times (x + 5) = 0 \\ ou \\ x + 5 = 0 \\ x = - 5 \\ \\ \\ c) \: \: \: {4x}^{2} - 12x = 0 \\ x \times (4x - 12) = 0 \\ ou \\ 4x - 12 = 0 \\ 4x = 12 \\ x = \frac{12}{4} \\ x = 3 \\ \\ \\ d) \: \: \: {2x}^{2} = 7x \\ {2x}^{2} - 7x = 0 \\ x \times ( 2x - 7) = 0 \\ ou \\ 2x - 7 = 0 \\ 2x = 7 \\ x = \frac{7}{2} = 3.5 \\ \\ \\ e) \: \: \: {2x}^{2} = 8x \\ {2x}^{2} - 8x = 0 \\ x \times (2x - 8) = 0 \\ ou \\ 2x - 8 = 0 \\ 2x = 8 \\ x = \frac{8}{2} \\ x = 4 \\ \\ \\ f) \: \: \: { - 2x}^{2} + 10x = 0 \\ x \times ( - 2x + 10) = 0 \\ ou \\ - 2x + 10 = 0 \\ - 2x = - 10 \\ - x = - \frac{10}{2} \\ - x = - 5 \: \: \: \: \: \times ( - 1) \\ x = 5 \\ \\ \\ g) \: \: \: 6 {x}^{2} - 10x = 0 \\ x \times (6x - 10) = 0 \\ 6x - 10 = 0 \\ 6x = 10 \\ x = \frac{10 \div 2}{6 \div 2} = \frac{5}{3}$