Question

Four brothers have ages which are consecutive even integers. If the product of the ages of the two middle brothers is 528, how old is the oldest brother?
**must use algebra**

Answer 1

Answer:

The oldest brother is of age $26$ years.

Step-by-step explanation:

As the age of four brothers are consecutive even integers.

We assume that the ages are $x,(x+2),(x+4),(x+6)$ as their respective ages.

And the age of the youngest brother $x$ yrs.

Age of the oldest brother $(x+6)$ yrs.

According to the question

Product of two middle brother that is $(x+2)(x+4) =528$

So we will arrange this in our equation and solve the quadratic.

$(x+2)(x+4) =528$

$x^{2}+4(x)+2(x)+8 =528$

$x^{2}+4(x)+2(x)+8-528=0$

$x^{2}+6(x)-520=0$

Solving the quadratic by using middle term splitting or directly with quadratic formula we can find the value of 'x' .

Here it is solved with quadratic formula:

Comparing with standard equation $ax^{2}+b(x)+c=0$,here $a=1,b=6\ and\ c=-520$.

$x= \frac{-b \pm \sqrt{b^2-4ac} }{2a} = \frac{-6 \pm \sqrt{6^2-4\times \ (-520)} }{2\times 1}$

$x=20,-26$

We will work with the positive value of (x) so the the age of the youngest brother $=(x)=20$ yrs.

And the age of the the oldest brother $=(x+6)=(20+6)=26$ years.

The age difference is of $(26-20)=6$ years.