Answer:
x²+1/x² = 51
Explanation:
Given x - 1/x = 7 ---(1)
We know the algebraic identity:
a²+b²-2ab = (a-b)²
Or
a²+b² = (a-b)²+2ab
Now,
x²+1/x²
= (x-1/x)²+2*x*(1/x)
= (x-1/x)²+2
:7²+2 [ from (1)] =
= 49+2
= 51
Therefore,
x²+1/x² = 51
Answer:
20
Step-by-step explanation:
-4 x (-5) = 20
Answer:
B
Step-by-step explanation:
Answer:
|AB| = √((7 - (-2))^2 + (-3 - 9)^2) = 15
|BC| = √((-2 - 7)^2 + (-3 - (-3))^2) = 9
|AC| = √((-2 - (-2))^2 + (-3 - 9)^2) = 12
Perimeter = 15 + 9 + 12 = 36
