Question

determine the value of "r" such that the solutions to the equation are -10 and 10 x^2 - r = 0

Answer 1

$x^2-r=0$

if x = 10 is a solution to the equation, then:

$\begin{gathered} 10^2-r=0 \\ 100-r=0 \\ 100=r \end{gathered}$

If x = -10 was used, the result would be the same, then the solution is r = 100