Experts have designed these Class 7 Maths Notes and Part 2 Chapter 7 Finding the Unknown Class 7 Notes for effective learning.
Class 7 Maths Chapter 7 Finding the Unknown Notes
→ Letters such as a, b, c,……….., x, y, z are used to represent numbers and are called letter-numbers. Their values are not fixed, as they stand for unknown quantities. These letter-numbers, used along with numerals, form algebraic expressions that follow the same rules as arithmetic. Such expressions often describe patterns or relationships seen in everyday life. In formulas, we use them to show how quantities are related and to make predictions.
→ In this way, a variable helps us express relationships and general rules in mathematics, especially in algebra and geometry. By evaluating these expressions for given values, we can find specific results and understand how changes in one quantity affect another.
→ An algebraic equation is a mathematical statement that indicates the equality of two algebraic expressions.
→ When the same operation is performed on both sides of an equation, equality is maintained.
→ Finding a solution to an equation means finding the values of the unknowns in the expressions such that the LHS is equal to the RHS.
→ The trial and error method is a problem solving method where multiple attempts are made to get a final solution.
→ Equations can often be solved by performing the same operation on both sides so that the value of the unknown becomes evident.
→ In ancient India, forming and solving equations using symbols was a key part of mathematical studies known as Bijaganita, the word bija means seed.
→ Brahmagupta discovered a general rule for solving equations like Ax+B=C x+D as
x=\(\frac{\mathrm{D}-\mathrm{B}}{\mathrm{A}-\mathrm{C}}\).