5/12 - y = 0,15
y = 5/12 - 0,15
y = 25/60 - 9/60
y = 16/60
y = 4/15
А₁ = -7, d = 3
S = (2a₁ +d(n - 1)) n/2 = (2 · (-7) + 3 · (10 - 1)) · 10 / 2 = (-14 + 3 · 9) · 5 = (-14 + 27) · 5 = 13 · 5 = 65
9,585:4,5=2,13
8,57+2,13=10,7
3,8*10,7=40,66
3 3/7 * 1 1/6 - 7/15 * 1 19/21 = 3 1/9
1) 3 3/7 * 1 1/6 = 24/7 * 7/6 = 24/6 = 4
2) 7/15 * 1 19/21 = 7/15 * 40/21 = (1*8)/(3*3) = 8/9
3) 4 - 8/9 = 3 целых 9/9 - 8/9 = 3 1/9
ДАНО
12/х + 12/(х+2) = 5.
Приводим к общему знаменателю.
12*(х+2) + 12*х = 5
24*х = 5-24 = -19
х = - 19/24 - ОТВЕТ