Question 517604: for each direct variation, find the constant of variation. then find the value of y when x=-0.5
a. y=4 when x=0.5
b. y=2 when x=3
Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website! for each direct variation, find the constant of variation. then find the value of y when x=-0.5
a. y=4 when x=0.5
b. y=2 when x=3
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I believe the constant of variation is another name for slope in a straight-line equation:
y=mx+b, m=slope, b=y-intercept
constant of variation or slope=∆y/∆x=rise/run=(y1-y2)/(x1-x2)
using two given points (.5,4) and (3,2) to find the slope:
m=(4-2)/(3-.5)=2/2.5=2/(5/2)=4/5
equation:
y=4x/5+b
using one of the points (3,2) to find b
2=4*3/5+b
2=12/5+b
10=12+5b
5b=10-12=-2
b=-2/5
equation:
y=4x/5-2/5
f(-.5)=4(-.5)/5-2/5
y=-2/5-2/5=-4/5
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