Algebraic expressions are like secret codes using letters and numbers! Instead of saying "some number," we use letters like x, y, z.
Simple Example:
If your age is unknown, we call it "x"
Your brother is 3 years older: x + 3
Your father is twice your age: 2x
These are algebraic expressions!
Shopping:
If pens cost ₹p each
5 pens cost: 5 × p = 5p
With ₹10 discount: 5p - 10
Cricket Score:
If runs per over = r
20 overs total: 20 × r = 20r
With 5 extras: 20r + 5
Geometry:
Perimeter of rectangle:
If length = l, width = w
Perimeter = 2l + 2w
In 3x + 2y - 5:
3x, 2y, -5 are called "terms"
x and y are "variables"
3 and 2 are "coefficients"
-5 is "constant"
Like Terms:
3x + 2x = 5x (same variable)
4y - y = 3y (same variable)
But 3x + 2y cannot be added (different)
In this chapter, we will learn:
Algebraic expressions help us:
For Class 7 Students (NCERT & JKBOSE)