
Answer: The number is -16
Step-by-step explanation: We start by assigning a letter to represent the unknown number. Hence, let the number be y.
One fourth of a number, or in this case, one-fourth of y, can also be written as 1/4 times y. That can now be expressed in its simplest form as
y/4.
Sixteen less than one-fourth of y, can also be re-written as
y/4 - 16.
Therefore if the question says, “sixteen less than one-fourth of a number is equal to -20...” we can now write out the question as follows
(y/4) - 16 = -20
For the left hand side of the equation we can find the LCM as 4, and that can now be written out as
(y - 64)/4 = -20
By cross multiplication we now have
y - 64 = -20 (4)
y - 64 = -80
Add 64 to both sides of the equation
y - 64 + 64 = -80 + 64
y = -16
Therefore the unknown number is -16