The answer is below hope it helps.
This is an equation involving x alone, so the most you can do is solve it:

Answer:
x² + x - 30
Step-by-step explanation:
Given
(x - 5)(x + 6)
Each term in the second factor is multiplied by each term in the first factor, that is
x(x + 6) - 5(x + 6) ← distribute both parenthesis
x² + 6x - 5x - 30 ← collect like terms
= x² + x - 30
The correct answer here is A) 55. This is because a positive integer is defined as any number greater than 0 and has no decimals/ fractions in it. Therefore, you would add 1+2+3+4+5+6+7+8+9+10, yielding 55 as your answer.
Answer: AC=12 cm
Step-by-step explanation:
To solve this problem you must apply the law of sines, as you can see below:

Where:
a=13
A=85.2°
B=71.6°
Therefore, you must solve for b, then, you obtain that the lenght AC asked in the problem above is:
