Answer:
-15.96
Step-by-step explanation:
A conjugate is a binomial with the sign inside changed. So the conjugate of (1/5 + 4i) is (1/5 - 4i)
Set the original and the conjugate next to each other and F.O.I.L. Multiply the first numbers of each binomial, the 1/5 and the 1/5 to get 1/25. This is the "F."
Multiply the outer members, the 1/5 and the 4i to get - 60i. This is the "O."
Multiply the inner numbers ( the + 4i and the 1/5) to get + 60i. This is the "I."
Multiply the positive 4i and the negative 4i to get 16i squared
The positive 60i and the negative 60i cancel each other out.
The i squared changes into - 1. This makes the 16 negative.
Add 1/25 to - 16 to get - 15.96
CALCULATE 5/8 + 3 1/4 x -3/6 - 2 5/12 = -3 5/12
The product has decreased by 80 %
<em><u>Solution:</u></em>
The product of the original numbers: xy
One number is decreased by 75 %
Let x be the number decreased by 75 %
new number = x - 75 % of x

Another number is decreased by 20 %
Let y be the number decreased by 20 %
new number = y - 20 % of y

<em><u>Now the product is given as:</u></em>

<em><u>Now we have to find the percent decreased</u></em>
Subtract new product and original product and then divide by original product . Multiply the result by 100 to get percentage

Here negative sign denotes decrease
Thus the product has decreased by 80 %