Advanced Math practice question

Answer: 25

(difference)² = (sum)² − 4 · (product) = 81 − 56 = 25. (The numbers are 7 and 2.)

Common wrong answers

If you answered 5

5 is the difference itself (7 − 2); the question asks for its square.

If you answered 53

Subtract 4 · 14 = 56, not 2 · 14 = 28: the identity is (sum)² − 4(product).

If you answered 81

81 is the square of the sum; subtract 4 times the product, 56.

More Advanced Math questions

• Very hard
  The function f(x) = x² + 6x + 5 is rewritten in the form f(x) = (x + a)² + b. What is the value of b?
• Very hard
  What is the solution to the equation 6/(x − 2) = 3?
• Very hard
  The polynomial p(x) = x³ − 4x has how many distinct real zeros?
• Very hard
  The polynomial p is defined by p(x) = x³ + ax² + bx − 12, where a and b are constants. If x − 2 is a factor of…
• Very hard
  The function f, defined by f(x) = 3000(1.331)^(x/12), gives the value, in dollars, of an investment x months a…
• Very hard
  In the xy-plane, the parabola y = x² − 4x + 7 and the line y = mx − 2, where m is a constant, intersect at exa…