Thread: Solve Proportions using cross products

My sister thinks these problems are unsolvable for x. I can't find any examples in my book. I know how to solve basic proportion problems, but these two are hard.

1. x : x-3 = x+4 : x

2. x+1 : 6 = x-1 : x

Thanks!

Hey BrokenRitual.

Try getting rid of the denominators and collect the terms.

For the first one we have x^2 + 4x =x^2 - 3x or 7x = 0 => x = 0 but this is a contradiction since x is on the denominator and can't be zero. So no solution exists.

You try the same kind of technique for the second one.

Hello, BrokenRitual!

Why do you say these are "hard"?

We have: .

Cross product: .

n . . . . . . . . . . . . .

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We have: .

Cross product: .

n . . . . . . . . . . . . .

. . . . . . . . . . .

. . . . . . . . .

. . . . . . . . . . . . . . . . . .