Answer:
[tex]2ab - 6a + 5b - 15[/tex]
Step-by-step explanation:
Given
[tex]2ab - 6a + 5b + \_[/tex]
Required
Fill in the gap to produce the product of linear expressions
[tex]2ab - 6a + 5b + \_[/tex]
Split to 2
[tex](2ab - 6a) + (5b + \_)[/tex]
Factorize the first bracket
[tex]2a(b - 3) + (5b + \_)[/tex]
Represent the _ with X
[tex]2a(b - 3) + (5b + X)[/tex]
Factorize the second bracket
[tex]2a(b - 3) + 5(b + \frac{X}{5})[/tex]
To result in a linear expression, then the following condition must be satisfied;
[tex]b - 3 = b + \frac{X}{5}[/tex]
Subtract b from both sides
[tex]b - b- 3 = b - b+ \frac{X}{5}[/tex]
[tex]- 3 = \frac{X}{5}[/tex]
Multiply both sides by 5
[tex]- 3 * 5 = \frac{X}{5} * 5[/tex]
[tex]X = -15[/tex]
Substitute -15 for X in [tex]2a(b - 3) + 5(b + \frac{X}{5})[/tex]
[tex]2a(b - 3) + 5(b + \frac{-15}{5})[/tex]
[tex]2a(b - 3) + 5(b - \frac{15}{5})[/tex]
[tex]2a(b - 3) + 5(b - 3)[/tex]
[tex](2a + 5)(b - 3)[/tex]
The two linear expressions are [tex](2a+ 5)[/tex] and [tex](b - 3)[/tex]
Their product will result in [tex]2ab - 6a + 5b - 15[/tex]
Hence, the constant is -15
