Răspuns:
Explicație pas cu pas:
1.
26 - 13 - 6 = 26 - 19 = 7
2.
36 = 2^2 * 3^2
54 = 2*3^3
cmmdc = 2*3^2 = 2*9 = 18
3.
x = 4y
x + y = 4y + y = 5y
2x - y = 8y - y = 7y
(x + y)/(2x - y) = 5y/7y = 5/7
4.
(1 x 4 + 3 x 5 + 5 x 6 + 6 x 7 + 2 x 8 + 2 x 9 + 1 x 10) : (1 + 3 + 5 + 6 + 2 + 2 + 1) = (4 + 15 + 30 + 42 + 16 + 18 + 10) : 20 = 135/20 = 6,75
