Question

пожалуйста помогите мне с алгеброй даю 25 баллов ​

Answer 1

1)

$\frac{2x - 1}{x}$

подставим

х=3

$\frac{2 \times 3 - 1}{3} = \frac{6 - 1}{3} = \frac{5}{3} = 1 \frac{2}{3}$

х= 1

$\frac{2 \times 1 - 1}{1} = \frac{1}{1} = 1$

х= -5

$\frac{2 \times ( - 5) - 1}{ - 5} = \frac{ - 10 - 1}{ - 5} = \frac{ - 11}{ - 5} = 2 \frac{1}{5} </p><p>$

х= ½

$\frac{2 \times \frac{1}{2} - 1}{ \frac{1}{2} } = \frac{1 - 1}{ \frac{1}{2} } = \frac{0}{ \frac{1}{2} } = 0$

х= -1,6

$\frac{2 \times ( - 1.6) - 1}{ - 1.6} = \frac{ - 3.2 - 1}{ - 1.6} = \frac{ - 4.2}{ - 1.6} = 2.625$

х= 100

$\frac{2 \times 100 - 1}{100} = \frac{200 - 1}{100} = \frac{199}{100} = 1.99$

2)

$\frac{3a - 7}{2a + 5}$

подставим

а= -2

$\frac{3 \times ( - 2) - 7}{2 \times ( - 2) + 5} = \frac{ - 6 - 7}{ - 4 + 5} = \frac{ - 13}{1} = - 13 </p><p>$

а= - 0,4

$\frac{3 \times ( - 0.4) - 7}{2 \times ( - 0.4) + 5} = \frac{ - 1.2 - 7}{ - 0.8 + 5} = \frac{ - 8.2}{4.2} = - \frac{41}{21} = - 1 \frac{20}{21}$

а = 0

$\frac{3 \times 0 - 7}{2 \times 0 + 5} = \frac{ - 7}{5} = - 1 \frac{2}{5}$

а = 2,5

$\frac{3 \times 2.5 - 7}{2 \times 2.5 + 5} = \frac{7.5 - 7}{5 + 5} = \frac{0.5}{10} = 0.05</p><p>$

3)

$\frac{ {b}^{2} + 6 }{3b - 4}$

подставим

b = 3

$\frac{ {3}^{2} + 6 }{3 \times 3 - 4} = \frac{9 + 6}{9 - 4} = \frac{15}{5} = 3$

b = 4,4

$\frac{ {4.4}^{2} + 6 }{3 \times 4.4 - 4} = \frac{19.36 + 6}{13.2 - 4} = \frac{25.36}{9.2} = \frac{317}{115} = 2 \frac{87}{115}$

b = 5

$\frac{ {5}^{2} + 6 }{3 \times 5 - 4} = \frac{25 + 6}{15 - 4} = \frac{31}{11} = 1 \frac{10}{11} </p><p>$

b = 6

$\frac{ {6}^{2} + 6 }{3 \times 6 - 4} = \frac{36 + 6}{18 - 4} = \frac{42}{14} = 3$