Решите уравнения: а) 15/(7-y) = 5 б) 42/y = 3 в) (12+y)/9 = 3 г) (14+х )/9 = 5 д) y -...

Question

Решите уравнения: а) 15/(7-y) = 5 б) 42/y = 3 в) (12+y)/9 = 3 г) (14+х )/9 = 5 д) y - 13/27 = 10/27 е) 4 1/5 + x = 7 4/5 ж) (8/15 + x) - 7/15 = 11/15 з) x/42 - 5/42 = 35/42
(Это дроби)

Answer 1

А)
15/(7-y) = 5
7-y=15:5
7-y=3
y=7-3
y=4

б)
42/y = 3
y=42:3
y=14

в)
(12+y)/9 = 3
12+y=3*9
12+y=27
y=27-12
y=15

г)
(14+х )/9 = 5
14+y=5*9
14+y=45
y=45-14
y=31

д)
y - 13/27 = 10/27
y = 10/27 + 13/27
y = 23/27

е)
4 1/5 + x = 7 4/5
x = 7 4/5 - 4 1/5
x = 3 3/5

ж)
(8/15 + x) - 7/15 = 11/15
8/15 + x - 7/15 = 11/15
1/15 + x = 11/15
x = 11/15 - 1/15
x = 10/15
x = 2/3

з)
x/42 - 5/42 = 35/42
x/42 = 35/42 + 5/42
x/42 = 40/42
x = 40/42 * 42
x = 40