Posted by **Amy** on Sunday, January 23, 2011 at 9:49pm.

1. Simplify the expression ((5x^-2)/(4x^2))^-2

2. (x)/(x^2-81)-(9)/(81-x^2) =

3. Let (-3,3) and (-6,_2) be points in the Cartesian plane. Find the distance between the points.

- Precalculus -
**Reiny**, Sunday, January 23, 2011 at 10:30pm
((5x^-2)/(4x^2))^-2

= (5x^-2)(4x^2)^2

= (5x^-2)(16x^4)

= 80x^2

2. Do you realize that 81 - x^2 = -(x^2 - 81)

so (x)/(x^2-81)-(9)/(81-x^2)

= x/(x^2 - 81) + 9/(x^2 - 81)

= (x-9)/((x+9)(x-9))

= 1/(x+9) , x ≠ 9

- Precalculus -
**Reiny**, Sunday, January 23, 2011 at 10:30pm
for #3

you should have a formula for the distance between 2 points.

## Answer this Question

## Related Questions

Precalculus - he distance between 2 points (x1,Y1) and (x2,y2) is given by d = ...

Precalculus - The distance between 2 points (z1,Y1) and (x2,y2) is given by d = ...

Physics - 1. Two points in a plane have polar coordinates (2.5 m, 30 degrees) ...

Physics - Two points in the xy plane have cartesian coordinates (4.6,-10) and (-...

Physics - Two points in the xy plane have Cartesian coordinates (2.00, -4.00) m ...

physics - Two points in a plane have polar coordinates (2.40 m, 40.0°) and (3.50...

maths - geometry - In a space with an orthonormal coordinate system consider the...

c++ - Distance between two 3-D points. Given two points in space (3-dimensional...

Math - If a plane has intercepts at 2a, 3a, and 4a along the three Cartesian ...

math:quick help - Let Fn be the nth number in the Fibonacci Sequence. Consider ...