Step-by-step explanation:
we divide both sides by 4 to single out the X
(4X) / 4 = (2/3)/4
simplify
X = 2/12

so.. as you can see, we use the decimal notation for the percentages... 65% is just 65/100 and 50% is just 50/100 and so on
so.. whatever the salted amounts are, we know they'll add up to (x+175)(0.50)
thus (0.30x) + (175)(0.65) = (x+175)(0.50)
solve for "x"
Given
Area of the regular pentagon is 6.9 cm².
Find out the perimeter of a regular pentagon
To proof
Formula
Area of regular pentagon is

As given in the question
area of regular pentagon = 6.9 cm²
now equating the area value with the area formula.

Now put
√5 = 2.24 ( approx)
put in the above equation

thus
a² = 4.01
a = √ 4.01
a = 2.0 cm ( approx)
As perimeter represented the sum of all sides.
i.e regular pentagon have five sides of equal length.
Thus
perimeter of the regular pentagon = 5 × side length
= 5 ×2.00
therefore the perimeter of the regular pentagon = 10cm
option c is correct
Hence proved