chem
barium chloride+ alumium sulphate »barium sulphate + allumium chloride (balance the equation step by step)
mathematics
How many ordered pairs of solutions (a,b) are there to a/b−b/a−2/a−2/b=0, where a and b are integers from −100≤a,b≤100?
geometry and combination
okay at least somebody give a hint
math
Suppose P is an invertible 3×3 matrix with real entries and P4=2P. Find the determinant of 7P.
math
What is the minimum value of N that will make this statement true: If we pick any N composite numbers from 1 to 1000, then we can find 2 numbers whose greatest common divisor is not 1. Details and assumptions You may use the fact that there are 168 primes from 1 to 1000.
math
N=2^(1!)!+2^(2!)!+...+2^(1000!)!? this is the actual series..
math
What are the last three digits of the number N=2(1!)!+2(2!)!+...+2(1000!)!?
maths
threesome
maths
ABCD is a convex cyclic quadrilateral such that AB=AD and ∠BAD=90∘. E is the foot of the perpendicular from A to BC, and F is the foot of the perpendicular from A to DC. If AE+AF=16, what is the area of ABCD?
maths
ABCD is a convex cyclic quadrilateral such that AB=AD and ∠BAD=90∘. E is the foot of the perpendicular from A to BC, and F is the foot of the perpendicular from A to DC. If AE+AF=16, what is the area of ABCD?
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