Pair of linear equations

b ## Class 10:

Pair of linear equations in 2 variables

• standard equation in linear -
  • ax + by + c = 0,
  • a,b not zero (ie) a^2 + b^ 2 / = 0
• solution of linear equation - every solution is a point on the line representing it

INTERSECTING

• one solution - unique
• consistent
• (a1 / a2) != (b1 / b2)

PARALLEL

• lines do not intersect
• no solutions
• inconsistent pair
• a1 = b1 != c1

COINCIDENT

• equivalent lines, ie. one can be derived from another equation
• infinitely many solutions
• dependent and consistent
• a1 = b1 = c1
  

Solving the linear equation

• graphical method of solving the equation
• substitution method
• elimination method

Ex.3.1

1. express in linear equation

Ex.3.2

1. form the linear equation
2. check the ratios and identify the type of lines formed

Ex.3.3

1. solve by substitution method

Ex.3.4

1. solve by elimination method

RD Sharma new