Answer:
Step-by-step explanation:
Let the missing number be 'x'
⇒[tex] \mathsf{15 + 9 = x(5 + 3)}[/tex]
Distribute x through the parentheses
⇒[tex] \mathsf{15 + 9 = 5x + 3x}[/tex]
Swap the sides of the equation
⇒[tex] \mathsf{5x + 3x = 15 + 9}[/tex]
Add the numbers
⇒[tex] \mathsf{5x + 3x = 24}[/tex]
Collect like terms
⇒[tex] \mathsf{8x = 24}[/tex]
Divide both sides of the equation by 8
⇒[tex] \mathsf{ \frac{8x}{8} = \frac{24}{8} }[/tex]
Calculate
⇒[tex] \mathsf{x = 3}[/tex]
Hope I helped!
Best regards!