412. Используя основное свойство дроби, найдите значение : 4х +1
72 18
1)
3)
11 22
60
4х +7
50
5
5х – 6
2)
39 13
=
57 8x - 5
4)
70
45
9

1) (4х+1)/11 = 50/22 2) 39/57 = 13/(8х-5)

22 : 11 = 2 - доп.множ. 39 : 13 = 3 - доп.множ.

2 * (4х + 1) = 50 3 * (8х - 5) = 57

4х + 1 = 50 : 2 8х - 5 = 57 : 3

4х + 1 = 25 8х - 5 = 19

4х = 25 - 1 8х = 19 + 5

4х = 24 8х = 24

х = 24 : 4 х = 24 : 8

х = 6 х = 3

3) 72/60 = 18/(4х+7) 4) (5х-6)/9 = 70/45

72 : 18 = 4 - доп.множ. 45 : 9 = 5 - доп.множ.

4 * (4х + 7) = 60 5 * (5х - 6) = 70

4х + 7 = 60 : 4 5х - 6 = 70 : 5

4х + 7 = 15 5х - 6 = 14

4х = 15 - 7 5х = 14 + 6

4х = 8 5х = 20

х = 8 : 4 х = 20 : 5

х = 2 х= 4