Curriculum
Course: Mathematics — First Preparatory
Login

Curriculum

Mathematics — First Preparatory

Text lesson

Linear Equations

Mathematics — First Preparatory

Linear Equations

Rules for solving an equation

Rules for solving an equation

  • We solve an equation by doing the same operation to both sides, which keeps the two sides equal.
  • In this way we isolate the variable on one side:
  • Add or subtract the same number on both sides to remove a constant term.
  • Multiply or divide both sides by the same number to remove a coefficient.
  • Remove brackets first, and simplify each side before solving.
  • If there are fractions, multiply both sides by the common denominator.
  • If the variable appears on both sides, collect the terms with the variable on one side and the numbers on the other side.

An equation with fractions

  • To solve (x + 1) ÷ 2 + x ÷ 3 = 4, multiply both sides by the common denominator 6.
  • This gives 3(x + 1) + 2x = 24.
  • Remove the bracket to get 3x + 3 + 2x = 24, so 5x = 21 and x = 21 ÷ 5 = 4.2.
  • Check: (4.2 + 1) ÷ 2 + 4.2 ÷ 3 = 2.6 + 1.4 = 4.
  1. Notice that the solution may be a decimal or a fraction
  2. and it does not have to be a whole number.
Linear Equations · 2 / 5