Each interior angle is 60° because all angles have to equal up to 180° so 180/3 = 60
The ONLY multiple of 11 that's between 70 and 80 is 77 .
We have that
<span>y=3x</span>²<span>+18x-21
using a graph tool
see the attached figure
the solutions are
x=-7x=1</span>
3.14 on the length. but if you add to a graph send another one to my comment and show me
explanation