Question

resolva as equações do 2° grau

a) x²-3x = 0

b)2y²-98=0

c) 5x²-3x- 2=0

Answer 1

${x}^{2} - 3x = 0 \\ delta = {b}^{2} - 4ac \\ = - 3 {}^{2} - 4 \times 1 \times 0 \\ = 9 - 0 \\ = 9 \\ x12 = \frac{ - b + - \sqrt{9} }{2a} \\ x12 = \frac{ - ( - 3) + - 3}{2 \times 1} \\ x1 = \frac{3 + 3}{2} \\ x1 = \frac{6}{2} \\ x1 = 3 \\ x2 = \frac{3 - 3}{2} \\ x2 = \frac{0}{2} \\ x2 = 0$