Question 1083170
{{{system(x+y=7,xy=12)}}}


3 and 4
-----could be done all in the head




More lengthy methods are possible.
<a href="https://www.algebra.com/my/FIND-RECTANGLE-DIMENSIONS-USING-GIVEN-PERIMETER-AND-AREA.lesson?content_action=show_dev">https://www.algebra.com/my/FIND-RECTANGLE-DIMENSIONS-USING-GIVEN-PERIMETER-AND-AREA.lesson?content_action=show_dev</a>
https://www.algebra.com/my/FIND-RECTANGLE-DIMENSIONS-USING-GIVEN-PERIMETER-AND-AREA.lesson?content_action=show_dev