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2010 AMC 10B · #25Polynomials

Let a>0a > 0 , and let P(x)P(x) be a polynomial with integer coefficients such that P(1)=P(3)=P(5)=P(7)=aP(1) = P(3) = P(5) = P(7) = a , and
P(2)=P(4)=P(6)=P(8)=aP(2) = P(4) = P(6) = P(8) = -a . What is the smallest possible value of aa ?

2009 AMC 10A · #11Algebraic Manipulation

One dimension of a cube is increased by 11 , another is decreased by 11 , and the third is left unchanged. The volume of the new rectangular solid is 55 less than that of the cube. What was the volume of the cube?

2008 AMC 10A · #7Exponents, Logarithms & Radicals

The fraction (32008)2(32006)2(32007)2(32005)2\frac{\left(3^{2008}\right)^2-\left(3^{2006}\right)^2}{\left(3^{2007}\right)^2-\left(3^{2005}\right)^2} simplifies to which of the following?

2008 AMC 10A · #18Triangles: Area & Pythagorean

A right triangle has perimeter 32 and area 20. What is the length of its hypotenuse?

2008 AMC 10B · #5Functions

For real numbers aa and bb , define a$ba \$b =(ab)2=(a-b)^2 . What is (xy)2$(yx)2(x-y)^2\$(y-x)^2 ?

2008 AMC 10B · #9Quadratics

A quadratic equation ax22ax+b=0ax^2 - 2ax + b = 0 has two real solutions. What is the average of these two solutions?

2008 AMC 10B · #13Sequences & Series

For each positive integer nn , the mean of the first nn terms of a sequence is nn . What is the 2008th term of the sequence?

2008 AMC 10B · #15Diophantine Equations

How many right triangles have integer leg lengths aa and bb and a hypotenuse of length b+1b+1 , where b<100b<100 ?

2008 AMC 10B · #23Diophantine Equations

A rectangular floor measures aa by bb feet, where aa and bb are positive integers with b>ab > a . An artist paints a rectangle on the floor with the sides of the rectangle parallel to the sides of the floor. The unpainted part of the floor forms a border of width 1 foot around the painted rectangle and occupies half …

2007 AMC 10A · #20Algebraic Manipulation

Suppose that the number aa satisfies the equation 4=a+a14 = a + a^{ - 1} . What is the value of a4+a4a^{4} + a^{ - 4} ?

2007 AMC 10A · #23Diophantine Equations

How many ordered pairs (m,n)(m,n) of positive integers, with mnm \ge n , have the property that their squares differ by 9696 ?

2006 AMC 10A · #8Quadratics

A parabola with equation y=x2+bx+cy=x^2+bx+c passes through the points (2,3)(2,3) and (4,3)(4,3) . What is cc ?

2006 AMC 10A · #11Coordinate Geometry

Which of the following describes the graph of the equation (x+y)2=x2+y2(x+y)^2=x^2+y^2 ?

2006 AMC 10B · #14Quadratics

Let aa and bb be the roots of the equation x2mx+2=0x^2-mx+2=0 . Suppose that a+1ba+\frac1b and b+1ab+\frac1a are the roots of the equation x2px+q=0x^2-px+q=0 . What is qq ?

2005 AMC 10A · #10Quadratics

There are two values of aa for which the equation 4x2+ax+8x+9=04x^2 + ax + 8x + 9 = 0 has only one solution for xx . What is the sum of those values of aa ?

2005 AMC 10A · #24Primes

For each positive integer m>1m > 1 , let P(m)P(m) denote the greatest prime factor of mm . For how many positive integers nn is it true that both P(n)=nP(n) = \sqrt{n} and P(n+48)=n+48P(n+48) = \sqrt{n+48} ?

2005 AMC 10B · #16Quadratics

The quadratic equation x2+mx+nx^2+mx+n has roots twice those of x2+px+mx^2+px+m , and none of m,n,m,n, and pp is zero. What is the value of n/pn/p ?

2005 AMC 10B · #22Divisibility & Factors

For how many positive integers nn less than or equal to 2424 is n!n! evenly divisible by 1+2++n?1 + 2 + \cdots + n?

2005 AMC 10B · #23Quadrilaterals & Polygon Areas

In trapezoid ABCDABCD we have AB\overline{AB} parallel to DC\overline{DC} , EE as the midpoint of BC\overline{BC} , and FF as the midpoint of DA\overline{DA} . The area of ABEFABEF is twice the area of FECDFECD . What is AB/DCAB/DC ?

2005 AMC 10B · #24Diophantine Equations

Let xx and yy be two-digit integers such that yy is obtained by reversing the digits of xx . The integers xx and yy satisfy x2y2=m2x^2 - y^2 = m^2 for some positive integer mm . What is x+y+mx + y + m ?

2004 AMC 10A · #18Sequences & Series

A sequence of three real numbers forms an arithmetic progression with a first term of 99 . If 22 is added to the second term and 2020 is added to the third term, the three resulting numbers form a geometric progression. What is the smallest possible value for the third term in the geometric progression?

2004 AMC 10A · #20Triangles: Area & Pythagorean

Points EE and FF are located on square ABCDABCD so that BEF\triangle BEF is equilateral. What is the ratio of the area of DEF\triangle DEF to that of ABE\triangle ABE ?

2004 AMC 10B · #6Number Properties

Which of the following numbers is a perfect square?

2004 AMC 10B · #10Sequences & Series

A grocer makes a display of cans in which the top row has one can and each lower row has two more cans than the row above it. If the display contains 100100 cans, how many rows does it contain?

2004 AMC 10B · #11Basic Probability

Two eight-sided dice each have faces numbered 11 through 88 . When the dice are rolled, each face has an equal probability of appearing on the top. What is the probability that the product of the two top numbers is greater than their sum?