Iwould appreciate if someone can me. at least the first 3 and 16, 18, 20

Lana's family entered a 5-kilometer race lana's average step length is about 0.5 meter how many steps will she need to take the finish

1. which answer is the solution set to the given inequality? 2x+6< 8 a. x e (-∞,1) b. x e [1,∞) c. x e (1,∞) d. x e (-∞,1] 2. which answer represents the given compound inequality in interval notation? x≥12 or x< -4 a. x e [-4, 12) b. x e (-∞, -4) u [12,∞) c. x e (-∞, -4] u (12,∞) d. x e (-4,12] 3. which answer is the solution set of the given compound inequality? 7> x+6 or x-2≥3 a. x e (-∞, 1) u [5,∞) b. x e (1, 5] c. x e (-∞, 1) ∩ [5,∞) d. x e [1,5) 4. which conjunction or disconjunction is equivalent to the given absolute value inequality? |x+3|> 12 a. x+3> 12 and x+3< -12 b. x+3< 12 and x+3> -12 c. x+3< 12 or x+3> -12 d. x+3> 12 or x+3< -12

Which is the correct formula to find the area of abc