1)x+x/4=15/8
2)(3/5-3/4): 3/40
3) (6a-6)(6a+6)-6a(6a+6) при а=5,5

1)

(4х+х)/4=15/8

5х/4=15/8

Про порцией

5х×8=4×15

40х=60

Х= 60/40

Х=6/4 = 3/2 = 1,5

2)

(3×4-3×5)/20 : 3/40 = -3/20 : 3/40 = -(3/20 × 40/3) = -1/20 × 40/1 = -2

3)

36а²-36-36а²-36а= -36(1+а)= -36×6,5 = -234