Dad's so funny. He's always looking at Cris' guess-and-check problems and going, "There's gotta be a faster way to do this, but I don't know how. ... Jess!" So I come and figure out the algebra for him. I gotta say, it certainly keeps my math skills sharp.
Today's was: Anna is three times as old as her brother Joey. In three years she will be two times as old as Joey. How old is Joey now?
It took me a bit, but I figured, okay, three times Joey's age now is Anna's age now. So Joey's age now is x and Anna's age now is y.
3x = y
Then 2 times Joey's age in three years is Anna's age in three years.
2 (x + 3) = y + 3
Well, y = 3x, so if we distribute the 2 through the parentheses and replace y with 3x we have:
2x + 6 = 3x + 3
-2x -3 -2x -3
3 = x
So Joey's age now is three.
I explain it to Dad and he's like... Wait... what? That's too confusing. Isn't there an easier way? ... Yeah. Guess and check. But he got it in the end. I still wonder why he worries about my SATs when I haven't had math in about 2 years and I can still figure that shit out.
Today's was: Anna is three times as old as her brother Joey. In three years she will be two times as old as Joey. How old is Joey now?
It took me a bit, but I figured, okay, three times Joey's age now is Anna's age now. So Joey's age now is x and Anna's age now is y.
3x = y
Then 2 times Joey's age in three years is Anna's age in three years.
2 (x + 3) = y + 3
Well, y = 3x, so if we distribute the 2 through the parentheses and replace y with 3x we have:
2x + 6 = 3x + 3
-2x -3 -2x -3
3 = x
So Joey's age now is three.
I explain it to Dad and he's like... Wait... what? That's too confusing. Isn't there an easier way? ... Yeah. Guess and check. But he got it in the end. I still wonder why he worries about my SATs when I haven't had math in about 2 years and I can still figure that shit out.