Question

Помогите пожалуйста решить уравнения срочно даю 50 баллов:
2x²+7x-9=0
3x²=18x
100x²-16=0
x²-16x+63=0

Answer 1

Ответ:

$2{x}^{2} + 7x - 9 = 0 \\ d = 49 + 72 = 121 = {11}^{2} \\ x1 = ( - 7 - 11) \div 4 = - 4.5 \\ x2 = ( - 7 + 11) \div 4 = 1$

$2) \: 3 {x}^{2} - 18x = 0 \\ 3x(x - 6) = 0 \\ x1 = 0 \\ x2 = 6 \\ 3)100 {x}^{2} - 16 = 0 \\ 100 {x}^{2} = 16 \\ {x}^{2} = \frac{16}{100} \\ x1 = - \frac{4}{10}=-0,4 \\ x2 = \frac{4}{10}=0,4$

$4){x}^{2} - 16x + 63 = 0 \\ d = 256 -252=4$

$x1 = \frac{16 - 2}{2} = 7 \\ x2 = \frac{16 + 2}{2} = 9$

Answer 2

Ответ:

1. x1=-4,5; x2=1

2. x1=0;x2=6

3. x=0,4

4. x1=7; x2=9