As the question is stated 1.5 does not equal 90. But if some units are added, then this could be true, like for example: 1.5 hours = 90 minutes, is a true equality.
What plus 11 equals -5?
6 x 15 = 90
105
15 + 80/90 = 143/9 = 15.888
81
90 divided by 6 equals 15.
0.45
6
15 times 6 = 90
Each of these factor pairs (multiply the numbers in parentheses) equals 90: (1, 90) (2, 45) (3, 30) (5, 18) (6, 15) (9, 10)
15z = 15 x 6 = 90
6 of them plus 10 = 100