Word problems on Quadratic Equations (6)

Question

Let there be two positive even integers such that the difference between them is 4. If their product is 96, find the numbers.

Solution :

Let the one even integer = `x`
The other even integer = `x + 4`

Given :

The product of integers = `96`
Therefore,
`(x)(x + 4) = 96`
`x^2 + 4x = 96`
`x^2 + 4x - 96 = 0`
Splitting the middle term,
`x^2 + 12x - 8x - 96 = 0`
Factoring out `x + 12`,
`x(x + 12) -8(x + 12) = 0`
`(x + 12) (x - 8) = 0`
By zero product rule,
`x + 12 = 0` or `x - 8 = 0`
`x = -12` `x = 8`
`x = {-12 , 8}`
Answer is x = 8 and x + 4 = 12, so the two positive even integers are 8 and 12.

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