СОР №3 по математике 5 класс. 2 вариант
Вычисли: а) 31/3+2 2/9*9/20; б) (5/12*1/4)*12.
Выполните действия: (11/5+1,2)*(0,4-1/20).
Решите уравнение: 5,4:0,6х=1,8.
Решите задачу: В классе 25 учащихся, 2/5 из них девочки, остальтные мальчики. Сколько девочек и мальчиков в хоре?
Выполните действия: (34/5+0,45)*1 2/3+(4,2-2/35):4 1/7.

ответ:

y = - 3x + 2 и y = kx - 5 пересекаются, значит мы приравниваем эти функции:

-3x + 2 = kx - 5

kx + 3x = 7

x(k + 3) = 7

1. x₁ = 7, тогда k должно быть -2 (так как 7 · (-2 + 3) = 7 · 1 = 7)

2. k + 3 = 7 ⇒ k = 4, тогда x₂ должно быть 1 (так как 1 · (4 + 3) = 7)

отсюда:

1. y₁ = -3 · 7 + 2 = -19

2. y₂ = 4 · 1 - 5 = -1 ≠ y₁ следовательно, подставим x и k из первого заключения:

y₂ = -2 · 7 - 5 = -14 - 5 = -19 = y₁

получится точка a:

a(7; -19)

найдём, при каком k функция y = kx + 4 проходит с точкой a, подставив значения из точки a(x; y):

y = kx + 4

-19 = k · 7 + 4

7k = -23

k = -23/7

пошаговое объяснение:

a little monkey was sitting on a tree. she was bored and she wanted to eat. she got down the tree and looked through the jungle to find a banana of a mango. but there was no fruits and even no tasty leafs. she was upset. she wandered through the jungle and meet her friends - green crocodile and bright parrot. parrot was very hungry too because he also couldn't find anything to eat. they decided to walk together. in a minute they noticed a huge yelow banana lying on the floor. monkey clutched it and at once many hunters with guns run to the glade.

friends started to run away. they ran through the bush and high grass and they saved their lives from the crafty hunters