Question

решите с объяснением и по действием

Answer 1

▪1.

$frac{39 {x}^{3}y }{26 {x}^{2} {y}^{2} } = frac{3x}{2 y }$
$frac{5y}{ {y}^{2} - 2y } = frac{5y}{y(y - 2)} = frac{5}{y - 2}$
$frac{ {a}^{2} - {b}^{2} }{3a - 3b} = frac{(a - b)(a + b)}{3(a - b)} = frac{a + b}{3}$

▪2.

а)
$frac{3 - 2a}{2a} - frac{1 - {a}^{2} }{ {a}^{2} } = frac{3a - 2 {a}^{2} -2 (1 - {a}^{2}) }{2 {a}^{2} } = frac{3a - 2 {a}^{2} - 2 + 2 {a}^{2} }{2 {a}^{2} } = frac{3a - 2}{2 {a}^{2} }$
б)
$frac{1}{3x + y} - frac{1}{3x - y} = frac{3x - y - 3x - y}{9 {x}^{2} - {y}^{2} } = frac{ - 2y}{9 {x}^{2} - {y}^{2} }$
в)
$frac{3}{b - 2} - frac{4 - 3b}{ {b}^{2} - 2b } = frac{3b - 4 + 3b}{b(b - 2)} = frac{6b - 4}{ {b}^{2} - 2b }$

▪3.
$frac{x - 6 {y}^{2} }{2y} + 3y = frac{x -6 {y}^{2} + 6 {y}^{2} }{2y} = frac{x}{2y} \ frac{x}{2y} = frac{ - 8}{2 times 0.1} = - frac{8}{0.2} = - frac{80}{2} = - 40$

▪4.

$frac{2}{x - 4} - frac{x + 8}{ {x}^{2} - 16} - frac{1}{x} = frac{2x(x + 4)}{x(x - 4)(x + 4)} - frac{x(x + 8)}{x(x - 4)(x + 4)} - frac{(x - 4)(x + 4)}{x(x - 4)(x + 4)} = frac{2 {x}^{2} + {x}^{2} - {x}^{2} - 8x - {x}^{2} + 16 }{x( {x}^{2} - 16) } = frac{ {x}^{2} - 8x + 16 }{x( {x}^{2} - 16) } = frac{ {(x - 4)}^{2} }{x( x - 4)(x + 4)} = frac{x - 4}{x(x + 4)}$