2-b-2%2B7-%D0%BF%D1%80%D0%B8-b%3D-13%2F14.jpeg "(b-7)2-b 2+7 При B=-13/14")
Simplifying Expressions with Substitution
This article explores how to simplify an expression by substituting a specific value for a variable.
Let's consider the expression (b - 7)² - b² + 7 and determine its value when b = -13/14.
Step 1: Substitute the value of 'b'
Replace each instance of 'b' in the expression with the given value, -13/14:
( -13/14 - 7 )² - ( -13/14 )² + 7
Step 2: Simplify the expression
Follow the order of operations (PEMDAS/BODMAS) to simplify the expression:
- Parentheses/Brackets: -13/14 - 7 = -111/14
- Exponents/Orders: (-111/14)² = 12321/196 and (-13/14)² = 169/196
- Multiplication and Division: (No operations in this step)
- Addition and Subtraction: 12321/196 - 169/196 + 7 = 12152/196 + 7 = 12850/196
Step 3: Simplify the result (optional)
The result can be simplified further by dividing both numerator and denominator by their greatest common factor, which is 2:
12850/196 = 6425/98
Therefore, the value of the expression (b - 7)² - b² + 7 when b = -13/14 is 6425/98.