How can I solve this ? I need to know steps please.. thank you ^^

Question

Hazel Anglin · Accepted Answer

#y=25# when #x=10#

In a lot of detail!

#color(blue)("Method")# Determine the value of #k# using #x=8 and y=20#. With this value for #k# substitute and determine the value of #y# when #x=10# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #color(blue)("Determine the value of "k)# Let #k# be some constant value (does not change) The format for; varies directly is #y=kx" "......Equation(1)# Known condition: at #color(red)(x=8)# the answer of y is #color(green)(y=20)# Substituting these values into #Equation(1)# we have #color(green)(y)=kcolor(red)(x)color(white)("ddd")->color(white)("ddd")color(green)(20)=kcolor(red)(8)# Remove the eighth from the right side of the = by dividing both sides by 8. #20/8=kxx8/8 larr" Note that "8/8=1# #20/8=k# #(20-:4)/(8-:4)=k=5/2# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #color(blue)("Determine "y" when "x=10)# #y=kxcolor(white)("ddd")->color(white)("ddd")y=5/2x# Given that #x=10# we have #color(white)("dddddddd")->color(white)("ddd")y=5/(cancel(2)^1)xxcancel(10)^5# #color(white)("dddddddd")->color(white)("ddd")y=5xx5=25#