if x=4-√7 find x²-1?
Answers
Answer:
Answer:
22 - 8√7
Step-by-step explanation:
Given,
x = 4 - √7
To Find :-
x² - 1
How To Do :-
First we need to find value of 'x²'[By applying formula of (a - b)²] and we need to subtract 1 from it
Solution :-
x² = ( 4 - √7)²
Comparing (a - b)² with (4 - √7)² :-
We can say , Values of :-
a = 4 , b = √7
→ (4 - √7)² = (4)² - 2(4)(√7) + (√7)²
= 16 - 8√7 + 7
= 23 - 8√7
x² - 1 = 23 - 8√7 - 1
= 22 - 8√7
∴ Value of 'x² - 1' = 22 - 8√7
Know More :-
Some Useful Algebraic formulas :-
1) (a + b)² = a² + 2ab + b²
2) (a - b)² = a² - 2ab + b²
3) (a + b) × (a - b) = a² - b²
Answer:
Hi hope this helps pls mark brainliest it would mean a lot
Step-by-step explanation:
x = 4 - √7
To Find :-
x² - 1
How To Do :-
First we need to find value of 'x²'[By applying formula of (a - b)²] and we need to subtract 1 from it
Solution :-
x² = ( 4 - √7)²
Comparing (a - b)² with (4 - √7)² :-
We can say , Values of :-
a = 4 , b = √7
→ (4 - √7)² = (4)² - 2(4)(√7) + (√7)²
= 16 - 8√7 + 7
= 23 - 8√7
x² - 1 = 23 - 8√7 - 1
= 22 - 8√7
∴ Value of 'x² - 1' = 22 - 8√7