Поомогите (4х-5)(х+3)=0

Question

Поомогите (4х-5)(х+3)=0

Answer 1

( 4х -5 ) ( х + 3 ) = 0
4х² + 12х - 5х - 15 = 0
4х² + 7х - 15 = 0
Д = 49 - 4 × 4 × (-15) = 49 + 240 = 289. √289 = 17.
х1 = -7 + 17 / 8 = 10/8 = 1,25.
х2 = -7 - 17 / 8 = -24 / 8 = -3.

Ответ : х1 = 1,25 ; х2 = -3.

Удачи))))

Answer 2

4х^2 + 12х - 5х - 15 = 0
4х^2 + 7х - 15 = 0
д = 49 + 240 = 289
корень из д = 17
х1 = (-7+17)/2*4 = 10/8 = 5/4
х2 = (-7-17)/ 2*4 = -24/8 = -3