Question

Assume that y varies inversely with x. If y = -21 when x = 4, find x when y = 7.

Answer 1

now find x by letting y = 7

Answer 2

okayy

Answer 3

wait i thought y=-84

Answer 4

@zzr0ck3r i dont get it

Answer 5

ok we have the equation
y=k/x
and they give us a point (4,-21) and another rpoint (?,7)
we need to figure out ?
so
first we don't even think about the x we need to figure out, because before we can do that we need to figure out what k is
so we use the first point to figure out what k is
y = k/x becomes -21 = k/4
so we solve for k
k=-84

now we know our equation is like this
y = -84/x (we now know what k is from our before work)
no we go back to that other point (?,7)
y = -84/x becomes 7 = -84/x
solve for x to get the answer

Answer 6

-1.3 ???

Answer 7

wait no its -12

Answer 8

7 = -84/x
x = -84/7
x = -12

Answer 9

YAY I GOT IT RIGHT thank youuuu

Answer 10

i have one more! Assume that y varies inversely as x. If y = -8 when x = -9, find y when x = 4.

Answer 11

do the exact same thing

Answer 12

y=k/x
use the first point (-9,-8) to solve for k
then you x=4 and solve for y