marmar29 wrote:y varies inversly with x
a) write this statment as an equation in x , y , & k
whc is pretty easy
b)if x decreses by 20% , find the percenatege change in y ?
please shw the steps
manar
The "decrease by 20%" is misleading - when dealing with direct and inverse relations, ALWAYS translate the change into multiplication division:
not "decrease by 20%"
BUT rather
"Multiply times (100%-20%)=80%".
By the same token, not "Increase by 25%" but rather "multiply times (100%+25%)=125%".
This is because direct / inverse relation is an increase in ratio:
Direct relation means in simple words "expand both y and x by the same constant - whatever you multiply x, multiply y by the same constant". If you multiply x by 2, multiply y by the same 2.
Inverse relation means "whatever you multiply x, divide y by the same constant". If you multiply x by 2, DIVIDE y by the same 2. Twice the x -> half the y.
)
