Algebra › Expressions and identities

Comparing coefficients

Solve the first problem 15 problems

These are 7 of the 15 problems. Sign in for free to see them all. Sign in

  1. Coefficients of a polynomial identity ●○○○○ 10 ptsIf (x+a)(x+8)=x2+bx+24(x+a)(x+8)=x^{2}+bx+24 for all values of xx, find the value of a+ba+b.
  2. Coefficients of a re-written quadratic ●○○○○ 10 ptsThe expression 2(x−3)2−122(x-3)^{2}-12 can be re-written as ax2+bx+cax^{2}+bx+c for some numbers a,b,ca, b, c. What is the value of 10a−b−4c10a-b-4c?
  3. Coefficients of an algebraic identity ●○○○○ 10 ptsThe equation ax+18=2(x−b)ax+18=2(x-b) holds for all values of xx. Work out the value of a−ba-b.
  4. Quadratic constraint on a shifted expression ●●○○○ 20 ptsGiven 6x2−4x−3=06x^{2}-4x-3=0, find the value of (x−1)2+x(x+23)(x-1)^{2}+x\left(x+\frac{2}{3}\right).
  5. Sum of coefficients in a shifted cubic expansion ●●○○○ 20 ptsIf the equation 1+x+x2+x3=a0+a1(1−x)+a2(1−x)2+a3(1−x)31+x+x^{2}+x^{3}=a_{0}+a_{1}(1-x)+a_{2}(1-x)^{2}+a_{3}(1-x)^{3} holds for all real xx, where a0a_{0}, a1a_{1}, a2a_{2}, a3a_{3} are real constants, find the value of a1+a2+a3a_{1}+a_{2}+a_{3}.
  6. Quadratic expression in shifted variables ●●○○○ 20 ptsGiven a=2009x+2007a=2009x+2007, b=2009x+2008b=2009x+2008, c=2009x+2009c=2009x+2009, find the value of a2+b2+c2−ab−bc−caa^{2}+b^{2}+c^{2}-ab-bc-ca.
  7. Possible values of c in a polynomial identity ●●●○○ 50 ptsGiven integers aa, bb and cc such that the equation (x+a)(x+b)+c(x−10)=(x−11)(x+1)(x+a)(x+b)+c(x-10)=(x-11)(x+1) holds for all xx, find all possible values of cc.

More in Expressions and identities