Question 731825
I will start the first two but you do the rest of what are needed yourself.


The muffins and milks
x muffins y quarts milk
{{{system(8x+2y=18,3x+y=7.5)}}}
Solve the system of simultaneous equations.  Choose either substitution or elimination.


The rectangle
w for width
w+3 for the length
Given, perimeter is 26 meters.
Find w and w+3.
{{{2(w+3)+2w=26}}}, and obvious what to do.