PLS HELP ASAP What are 3 different methods for solving systems of equations and when would you use each one? (10 pts)

How do you graph the solution set to a system of linear inequalities in two variables? (10 pts)

How do you determine if a system of linear equations has one solution, no solutions or infinitely many solutions? (10 pts)

Ihave a 69 and an 82. the 69 is worth 40% of my grade and the 82 is worth 15%. can someone tell me my current average grade.

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?

What are the solutions of the system? solve by graphing. y = x^2 + 3x + 2 y = 2x + 2