Question

Aflați numărul necunoscut:
97 : (4x + 1) = 10 rest 7
(4m + 7) : 7 = 7 rest 6
65 : (10 + 3y) = 4 rest 1
(100 - 5n) : 9 = 8 rest 3
75 : (15 - 2a) = 10 rest 5 DAU COROANA!!!!!!!!!!!

Answer 1

97 : (4x + 1) = 10 rest 7
97 = 10(4x + 1) + 7
97 = 40x + 10 + 7
97 - 10 - 7 = 40x
x = 80 : 40
x = 2
(4m + 7) : 7 = 7 rest 6
4m + 7 = 7 * 7 + 6
4m = 49 + 6 - 7
4m = 48
m = 12
65 : (10 + 3y) = 4 rest 1
65 = 4(10 + 3y) + 1
65 = 40 + 12y + 1
65 - 40 - 1 = 12y
y = 24 : 12
y = 2
(100 - 5n) : 9= 8 rest 3
100 - 5n = 8 * 9 + 3
- 5n = - 100 + 75
n = 25 : 5
n = 5
75 : (15 - 2a) = 10 rest 5
75 = 10(15 - 2a) + 5
75 = 150 - 20a + 5
75 - 150 - 5 = - 20a
- 80 = - 20a
a = 80 : 20
a = 4