Question

find the missing number so that the equation has infinitely many solutions. -3x + \square = -3(x - 5)

Explanation:

Step1: Expand the right-hand side

Use distributive property: $a(b-c)=ab-ac$
$-3(x - 5) = -3x + 15$

Step2: Match terms for infinite solutions

For $-3x + \square = -3x + 15$ to have infinitely many solutions, the constant terms must be equal.
$\square = 15$

Answer:

15