#27. First cross multiply 2 (2a-3) = 3 (a-1) next use the distribute property on both sides 4a - 6 = 3a - 3 combine like terms, subtract 3a from both sides and add 6 to both sides a = 3
#28 cross multiply 3x = 4, then divide both sides by 3 x = 4/3
#30 add 1/4 to both sides 3/x = 1/2 + 1/4, find a common denominator for the right side fractions 3/x = 2/4 + 1/4 = 3/4 therefore, x = 4
