Answer:
[tex]\boxed{\sf -\dfrac{18}{5}}[/tex].
Step-by-step explanation:
In the given equation [tex]\sf (2x + 5)(-mx + 9) = 0[/tex], the solutions [tex]\sf x = -\dfrac{5}{2}[/tex] and [tex]\sf x = \dfrac{3}{2}[/tex] indicate the values of [tex]\sf x[/tex] that make the equation true.
To find the value of [tex]\sf m[/tex], we can set each factor equal to zero and solve for [tex]\sf m[/tex]:
1. Set [tex]\sf 2x + 5[/tex] equal to zero:
[tex]\sf 2x + 5 = 0[/tex]
Solve for [tex]\sf x[/tex]:
[tex]\sf 2x = -5[/tex]
[tex]\sf x = -\dfrac{5}{2}[/tex]
2. Set [tex]\sf -mx + 9[/tex] equal to zero:
[tex]\sf -mx + 9 = 0[/tex]
Solve for [tex]\sf x[/tex]:
[tex]\sf -mx = -9[/tex]
[tex]\sf x = \dfrac{9}{m}[/tex]
Now, compare the values of [tex]\sf x[/tex] from the solutions:
[tex]\sf x = -\dfrac{5}{2} \quad \text{and} \quad x = \dfrac{9}{m}[/tex]
Since these are the same solutions, we can set them equal to each other:
[tex]\sf -\dfrac{5}{2} = \dfrac{9}{m}[/tex]
Now, solve for [tex]\sf m[/tex]:
[tex]\sf m = -\dfrac{9}{\dfrac{5}{2}} = -\dfrac{9}{1} \times \dfrac{2}{5} \\\\ = -\dfrac{18}{5}[/tex]
So, the value of [tex]\sf m[/tex] is [tex]\boxed{\sf -\dfrac{18}{5}}[/tex].