Someone help if you can

51

Step-by-step explanation:

all of the angles in a triangle will add up to equal 180

so to find the missing angle we just subtract the given angles from 180

180-43-86=51

so the missing angle is 51

x= 51

Step-by-step explanation:

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is:

step-by-step explanation:

∆abc has the points a(1, 7), b(-2, 2), and c(4, 2) as its vertices. formed with the point d(1, 2) as its third vertex, then ∆abd is triangle.