Question

3x-2y=5
-5x+2y=9
elimintion method

Answer 1

Step-by-step explanation:

Can be solved in 3 ways:

Substitution - can rearrange equation 2 to for x = 2y-5. Then substitute this in to equation 1 to form, 3(2y-5)+2y = 9. Multiply out the brackets and rearrange to form 8y = 24, so y=3 (would be explained step by step on whiteboard). Then substitute value for y into the equation: x-2(3)= -5, so x-6= -5, therefore x = 1.

Elimination:Alternate signs for y in each equation, so can add the equations together to cancel them out. This would form 4x = 4, therefore x = 1. Then substitute in the x value into one of the equations (same principle as in substitution method), 1-2y = -5. 2y = 6, therefore y = 3.

Graph:Could draw a graph for each line, and see the x and y co-ordinates at which they intersect. Good method for visualising the concept of solving the equation, but not time-efficient.