Question 1155399
Just to pick two of them and solving:


#4
{{{- x^3 + 22x^2 - 121x = 0}}}
{{{-x(x^2 - 22x + 121) = 0}}}
{{{-x (x - 11^2) = 0}}}
{{{-x (x - 11)* ( x + 11) =0}}}
Look there and see THREE factors to equate to 0.
They are  0, 11, & -11.




#15. 
The product of two consecutive positive integers is 72. Find the integers.
{{{n(n + 1)= 72}}}
If you do not need to solve a quadratic equation then basic fact is  72=9*8, so the solution is n=8.
(OR, -9 and -8 are the two factors, so n=-9 OR n=8)


If you are required to use as quadratic equation and solve, then {{{n^2+n-72=0}}}

and you could factorize into  {{{(n+9)(n-8)=72}}}



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Those two ARE done for you, STEP-BY-STEP.