8х + 16 = 0,
8х = -16,
х = -16 : 8,
х = -2,
3х - 21 ≤ 0,
3х ≤ 21,
х ≤ 7,
8х² - 12х + 1 = 0,
Д = (-12)² - 4*8*1 = 144 - 32 = 112,
х1 = (12 + 4√7) / 2*8 = (3 + √7)/4,
х2 = (12 - 4√7) / 2*8 = (3 - √7)/4,
(3,05 - 2,125 * 3,2) : 5/6 + 1 1/6 =
= (3,05 - 6,8) * 6/5 + 1 1/6 =
= -3,75 * 6/5 + 1 1/6 =
= -375/100 * 6/5 + 1 1/6 =
= -9/2 + 7/6 = -27/6 + 7/6 = -20/6 = -3 1/3,
(а²+10а+25)/(а²-25) =
= (а+5)²/(а-5)(а+5) = (а + 5)/(а - 5),
(в + 5)² = в² + 10в + 25,
36ву - 9су = 9у * (4в - с),
(64в⁻⁶)⁻¹⁾⁶ = 64⁻⁶°⁽⁻¹⁾⁶⁾ = 64¹ = 64
1) 12 3/5 - 7 1/6 = 63/5 - 43/6 = (378-215)/30 = 163/30
2) 163/30 + 2 3/10 = 163/30 + 23/10 = (163+69)/30 = 232/30 = 7 22/30 = 7 11/15