a)
X × 4 - 32:4=17
X × 4 = 17 + 8
X × 4 =25
X= 25:4
X= 6.25
b)
(X× 6 + 242:2) - 900= 97
X× 6 + 121 = 900 +97
X× 6 + 121 =997
X × 6 = 997-121
X= 876:6
X= 146
c)
[(4 × 72 - 72:8 ) : X + 35] × 6 +12=276
[(4 × 72 - 9) : X + 35] × 6 = 276-12
(288-9):X + 35= 264:6
279:X=44-35
279 :X= 9
X=279:9
X=31
d)
(X:2)+(3 ×123- 4×53)=257
(X:2)+(369 -212)=257
(X:2)+157=257
X:2=257-157
X:2=100
X=100×2
X=200