Решите уравнения пж...

Question

Решите уравнения пж 3(5+y)=19-5y 7c-4(c+4)=4(3-c) 2,14a+6,28=2,64a+9,78 -0,82-(3,18+0,06p)=3,94p-2p

Answer 1

1) 3(5 + y) = 19 - 5y

15 + 3y = 19 - 5y

3y + 5y = 19 - 15

8y = 4

y = 4/8

y = 1/2

2) 7c - 4(c + 4) = 4(3 - c)

7c - 4c - 16 = 12 - 4c

7c = 12 + 16

7c = 28

c = 28/7

c = 4

3) 2,14a + 6,28 = 2,64a + 9,78

2,14a - 2,64a = 9,78 - 6,28

- 0,5a = 3,5

a = 3,5/ (-0,5)

a = - 7

Comments

4) решить не получилось(((