Let's call x= length of the shorter side
the long side is 15 + 3 times the shorter side so: 15+3*x
and we know the area of a rectangle is: short side * long side
so
150= x * (15+3*x)
and now we just solve the equation:
To solve this we can use the bhaskara formula
0= 3x2+15x-150
a= 3 b=15 c=-150
bhaskara formula=
you replace the values and we get two x:
x1: 5
x2: -10
and length can't be negative so the answer is:
the length of the shorter side is: 5