Name: Ann Marie Devereux
Who is asking: Student
Level: Secondary

Question:
hi there!!, I guess I have a problem!!!

• 3x+4y=10 (over)
  4x+y=9

• 2x=5y+3 (over)
  x=3y+1

please help!!!
Maria

Lets consider the first problem. This pair of equations is called a system of linear equations (system because there is more than one and linear because the graph of each equation is a line in the plane). What you are looking for is a pair of numbers x and y that satisfy both equations. Geometrically you are looking for the coordinates of the point where the two lines intersect.

The standard technique to solve such a pair of equations is to find an equivalent pair of equations that have the same coefficient for one of the variable. What I plan to do is to multiply both sides of the second equation by 4 and this will result in 4 being the coefficient of y in this equation. Hence I will have two equations, both of which have 4 as the coefficient of y.

Now subtract the first equation from the second equation

Thus

Cheers,
Penny