Can some one help me please What is the difference of the values of the two variables in this system of equations?

y = 2x + 1
x + 3y = 10
A. 0
B. 1
C. 2
D. 3

At a point on the ground 50 meters from the foot of a tree, the angle of elevation to the tree is 48°. find the height of the tree to the nearest meter.

Given: ae ≅ ce ; de ≅ be prove: abcd is a parallelogram. we have that ab || dc. by a similar argument used to prove that △aeb ≅ △ced, we can show that △ ≅ △ceb by. so, ∠cad ≅ ∠ by cpctc. therefore, ad || bc by the converse of the theorem. since both pair of opposite sides are parallel, quadrilateral abcd is a parallelogram.

60 musicians applied for a job at a music school. 14 of the musicians play both guitar and drums, 28 play drums, 18 play the guitar. what is the probability that the applicant who gets the job plays drums or guitar?