Last year , there were 30 male members and 20 female members in a chess club . this year , the number of male members is decreased by r% while the number of female members is increased by r% . if the number of male members is equal to that of female members this year , find the value of r .can anyone explain to me ? thks \（> ∀< ）/

The r% of a quantity x is computed by dividing x in 100 parts, and considering r of such parts. So, the r% of the male is

and similarly, the r% of female is

The number of males decreased by this quantity, so now it is

and the number of female increased by this quantity, so now it is

we know that these two new counts are the same number, so we can build and solve the equality

Subtract 20 and add 0.3r from both sides:

Divide both sides by 0.5 to solve for r:

Let's check the answer

The 20% of 30 is , while the 20% of 20 is 4. So, we are stating that which is true because both expressions evaluate to 24.

option 2 is correct.

step-by-step explanation:

we are given two inequality equation

x+y> 5 and -3x+2y< -2

first we draw the graph of both function using t-table method

equation: x+y> 5

for x=0, y=5

for x=-5, y=0

table:

x   :   0     5

y   :   5     0

test point (0,0) , 0> 5

false

equation: -3x+2y< -2

for x=0, y=-1

for x=2, y=4

table:

x   :   0     2

y   : -1       4

test point (0,0) , 0< -2

true

now we draw the graph. see the attachment for graph.

common region would be solution set.

option 2 is correct.