Question

Быстро !!! 1 задание!!

Answer 1

Ответ:

1) x×(0,16x-4)-(0,4x+1)(0,4-1)=0

0,16x²-4x-(0,4²×x²-1)=0

$\frac{4}{25} {x}^{2} - 4x - (( \frac{2}{5}) {}^{2} \times x {}^{2} - 1) = 0$

$\frac{4}{25}x {}^{2} - 4x - ( \frac{4}{25} x {}^{2} - 1) = 0$

$\frac{4}{25} x {}^{2} - 4x - \frac{4}{25} x {}^{2} + 1 = 0$

-4x+1=0

-4x=-1

$x = \frac{1}{4}$

Или x=0,25

2) (2,1-x)(2,1+x)+0,49x+x²=0

2,1²-x²+0,49x+x²=0

$( \frac{21}{10} ) {}^{2} + 0.49x = 0$

$\frac{441}{100} + 0.49x = 0$

$0.49x = - \frac{441}{100}$

x=-9

3) (5-6x)²+58x=36x²-12

25-60x+36x²+58x=36x²-12

25-60x+58x=-12

25-2x=-12

-2x=-12-25

-2x=-37

$x = \frac{37}{2}$

Или x=18,5

4) 80x-(7x+6)²+49x²=-15

80x-(49x²+84x+36)+49x²=-15

80x-49x²-84x-36+49x²=-15

-4x-36=-15

-4x=-15+36

-4x=21

$x = - \frac{21}{4}$

Или x=-5,25