Question

аллалалалаьаьаьададдада​

Answer 1

1. В

$\frac{3x - 0.5}{2} = \frac{3 \times 0.3 - 0.5}{2} = \frac{0.9 - 0.5}{2} = \frac{0.4}{2} = 0.2$

2. Г

$9 + x≠0, \: \: x≠ - 9$

3. Г

$\frac{15b}{5a} = \frac{3 \times 5 \times b}{5 \times a} = \frac{3b}{a}$

4. В

$8 {y}^{5} \div 4 {y}^{3} = 2 {y}^{2}$

умножаем всю дробь на это число.

$\frac{x}{4 {y}^{3} } = \frac{x \times 2 {y}^{2} }{4 {y}^{3} \times 2 {y}^{2} } = \frac{2x {y}^{2} }{8 {y}^{5} }$

5. А

$\frac{5a - 5b}{10(a - b)} = \frac{5(a - b)}{10(a - b)} = \frac{5}{10} = \frac{1}{2}$

6.

$\frac{ {y}^{2} - 36}{6 {y}^{2} - {y}^{3} } = \frac{ {y}^{2} - {6}^{2} }{ {y}^{2} (6 - y)} = \frac{(y - 6)(y + 6)}{ - {y}^{2} (y - 6)} = \frac{y + 6}{ - {y}^{2} } = - \frac{y + 6}{ {y}^{2} }$

7.

$\frac{ {x}^{5} + 1 }{ {x}^{7} + {x}^{2} } = \frac{ {x}^{5} + 1}{ {x}^{2} ( {x}^{5} + 1) } = \frac{1}{ {x}^{2} }$

$\frac{1}{ {x}^{2} } = \frac{1}{ {( - \frac{1}{3} )}^{2} } = \frac{1}{ \frac{1}{9} } = 9$

8.

$\frac{9 {x}^{2} - 12xy + 4 {y}^{2} }{18x - 12y} = \frac{ {(3x)}^{2} - 2 \times 3x \times 2y + {(2y)}^{2} }{18x - 12y} = \frac{ {(3x - 2y)}^{2} }{6(3x - 2y)} = \frac{(3x - 2y)(3x - 2y)}{6(3x - 2y)} = \frac{3x - 2y}{6}$