Question

срочно
Решите уравнение 2 x² + 7 х - 9=0​

Answer 1

Ответ:

2х^2+7х-9=0

D=49+72=121

x=-7-11/4=-9/2

x2=-7+11/4=4/4=1

Answer 2

$2x^{2} +7x-9=0.$

$a=2, b=7,c=-9.$

$D=b^{2} -4ac=7^{2} -4*2*(-9)=49+72=121.$

$x_{1} =\frac{-b+\sqrt{D} }{2a} =\frac{-(7)+\sqrt{121} }{2*2} = \frac{-7+11}{4} =\frac{4}{4} =1.$

$x_{2} =\frac{-b-\sqrt{D} }{2a} =\frac{-(7)-\sqrt{121} }{2*2} =\frac{-7-11}{4} =\frac{-18}{4} =-4,5.$

Ответ: х₁ = 1, х₂ = -4,5.