I analyzed the followingFour year ago, woman was twice as old together Sam. 4 years on native now, Sam will certainly be 3/4 that Jane's age. Just how old is jane now?into:J - 4 = 2S3/4J = S + 4although I involved the answer easily enough through guess-and-check, for some reason I can't do it occupational out with simplifying the equation.My first instinct to be to do J=2S + 4 and also sub that into the bottom, getting3/4(2S + 4) = S + 41.5S + 3 = S + 40.5S = 1And that's no right. I tried the a bunch of other ways and also couldn't do it occupational out choose this. Would certainly be much appreciated if someone might demonstrate the procedure of this simplification/solution
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It helps to go step-by-step in such problems.
You are watching: Four years ago jane was twice as old as sam
Let Jane's existing age = J Sam's existing age = S
"Four year ago, woman was twice as old together Sam."
Age that Jane four years earlier = J -4 Sam's period four years earlier = S - 4
So => (J-4) = 2*(S-4)
Simplifying it gives us (2S - J) = 4 ---- Equation number 1
"Four years on from now, Sam will certainly be 3/4 the Jane's age"
Jane's period four year from now = J + 4 Sam's age four year from now = S + 4
So, (J+4)*3/4 = S + 4 3J + 12 = 4S + 16
=> 4S - 3J = -4 ----- Equation number 2
Now, solve Equation number 1 and also 2. To get the compelled answer.
You take it Jane's present age to be her age four year from currently when friend said
"3/4J = S +4"
And that four years ago, woman was twice as old together Sam is today. When you said
J - 4 = 2S
Hope it helped!
Op · 9y
Aahh, thank you. I resolved it slightly in different way after realizing that error :Simplified first equation to J = 2S - 4 and subbed 2S - 4 into the 2nd equationS + 4 = 3/4 (2s)4S + 16 = 6S16 = 2S , S=8 and plugged that ago into the an initial equation
You've translated incorrectly. Your an initial equation is a translate into of "Four year ago, jane was twice as old as Sam is now" however the intended translation is that "Four year ago, woman was double as old as Sam was 4 years ago.
See more: Which System Of Linear Inequalities Has The Point (2 1) In Its Solution Set
Op · 9y
Had a feeling that's where I walk wrong, thanks
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