Answer:
a = 3
Explanation:
Expand the given expression and compare like terms on both sides
Given
ax(2x + y - 5) = 6x² + 3xy - 15x ← distribute left side
2ax² + axy - 5ax = 6x² + 3xy - 15x
Compare coefficients of the x- terms, that is
- 5a = - 15 ( divide both sides by - 5 )
a = 3