It is given in the question that
You are buying a new printer and a new scanner for your computer and you cannot spend over $150. The printer you want costs $80.
Let the price of scanner be $ x .
So we have

Subtracting 80 from both sides

It means , the price should be not more then $70 .
Therefore in case, the price of scanner is $75, then you will not remain within your budget .
For a 30-60-90 triangle the sides always have the same relationship
Short leg = a
Long leg = a√3
Hypotenuse = 2a
BC is the short leg of ∆ABC
Given BC = 2
BC = a
Therefor
a = 2
AB = 2a = 4
AC = a√3 = 2√3
For ∆ACD
As above AC = 2√3
Since AC is the hypotenuse of ∆ACD
2a = 2√3
a = √3
CD = a = √3
AD = a√3 = 3
For ∆BCD
As above
BC = 2
CD = √3
Since BC is the hypotenuse of ∆BCD
2a = 2
a = 1
DB = a = 1
A bell ringing is the answer
X - Jack's age
y - Susan's age
Jack is 27 years older than Susan.

In 5 years he will be 4 times as old as she is.

The system of equations:

Jack is 31 years old and Susan is 4 years old.