Idon’t understand this question

the area of a parallelogram is 240. if the base is reduced to one-fourth its original length and it’s height is doubled, what is the new area?

a. 30
b. 60
c. 120
d. 240

120 units² (Answer C)

Step-by-step explanation:

The area of a parallelogram of base b and height h is A = bh, and here

A = bh = 240 units².

Doubling the height would give us a new height of 2h, and taking a quarter of the original base (length) would give us a new base (length) of b/4.

                                                                    240 units²

Solving A = bh = 240 units² for h yields

                                                                           b

and then substituting this result for h in the new equation

A = (2h) · (b/4) yields:

            240 units²                     2 · (240 units²)

     (2 · ) · (b/4), or = 120 units² (Answer C)

                    b                                       4

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.