(30+18):6 = 30:6+18:6 = 30:6+3
(48+12):6 = 48:6+12:6 = 8+2
(16+8):4 = 16:4+8:4 = 4+2
(28+12):4 = 28:4+12:4 = 7+3
9(540+x)=252
4860+9x=252
9x=252-4860
9x=4608
x=512
<span>28/60 + 9/60 = 37/60</span>
<span>а) a+b × c+b × d = a+b × (c+d)
б) a + b × c + b × d = a - b × (-c-d)
в) a - b × c + b × d = a + b × (-c+d)
г) a - b × c + b × d = a - b × (c-d)
д) a + b × c - b × d = a + b × (c-d)
е) a + b × c - b × d = a - b × (-c+d)
ж) a - b × c - b × d = a + b × (-c-d)
з) a - b × c - b × d = a - b × (c+d)</span>