Answer:
x = 18.5 cm
Explanation:
We are given the expression as well as value of the area of the shape, and therefore we can equate these two:
Now, in order to find the value of
, we have to make it the subject:
Expanding brackets and simplifying:
⇒
⇒
Multiplying the brackets on the top part of the fraction and simplifying:
⇒
⇒
We can remove the denominator from the fraction by dividing the top part of the fraction by 2:
⇒
Now we can collect like terms together:
⇒
Subtract 783 from both sides:
⇒
⇒
Finally, we can use the quadratic formula to find the value of
:
,
where:
a = 2
b = 5
c = -777.
∴
⇒
⇒
⇒
We have to use the positive value of
because length cannot be a negative number:
⇒
⇒
⇒
∴ The length of the side represented by
is 18.5 cm.