1)1 9/16 ÷ 3/8 = 25/16 ÷ 3/8 = 25/16 × 8/3 =200/48= 25/6 = 4 1/6
2)4 1/6 - 1/8 = 25/6 - 1/8 =<span> </span><span>(25 × 4 - 1 × 3)/24 = 100/24 - 3/24 = 97/24 = 4 1/24
ответ: 4 1/24</span>
1)6-5=1 3)2+4=6 5)4-1+2=5
2)4+1=5 4)6-3=3 6)3+1-2=2
Раскрываем скобки.
1) x(x^2-2) = x^3 + 8
x^3 - 2x = x^3 + 8
-2x = 8
x = -4
2) (x+5)(x-4) = x^2 + 18
x^2 + 5x - 4x - 20 = x^2 + 18
x - 20 = 18
x = 38
3) (x+7)(x-7) - (x-3)^2 = 53
Здесь два раза применим формулу разности квадратов.
(x^2 - 49) - (x-3)^2 = 53
x^2 - (x-3)^2 = 53+49
(x-x+3)(x+x-3) = 102
3(2x - 3) = 3*34
2x - 3 = 34
x = (34+3)/2 = 37/2 = 18,5