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Jon is 3 years younger than Laura. The product of their ages is 1,330. If [tex][tex]$j$[/tex][/tex] represents Jon's age and [tex][tex]$j+3$[/tex][/tex] represents Laura's age, what value of [tex][tex]$j$[/tex][/tex] could be Jon's age?

[tex]\[ j = \boxed{\ } \][/tex]



Answer :

To solve for Jon's age [tex]\( j \)[/tex], we start with the information provided:
- Jon is 3 years younger than Laura.
- The product of their ages is 1,330.
- If [tex]\( j \)[/tex] represents Jon's age, then [tex]\( j + 3 \)[/tex] represents Laura's age.

First, set up the equation representing the product of their ages:

[tex]\[ j \times (j + 3) = 1330 \][/tex]

Next, simplify and rearrange the equation to form a standard quadratic equation:

[tex]\[ j^2 + 3j - 1330 = 0 \][/tex]

At this step, we need to solve the quadratic equation for [tex]\( j \)[/tex].

Using the quadratic formula [tex]\( j = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)[/tex], where [tex]\(a = 1\)[/tex], [tex]\(b = 3\)[/tex], and [tex]\(c = -1330\)[/tex]:

Calculate the discriminant:
[tex]\[ \Delta = b^2 - 4ac = 3^2 - 4(1)(-1330) = 9 + 5320 = 5329 \][/tex]

Take the square root of the discriminant:
[tex]\[ \sqrt{5329} = 73 \][/tex]

Plug the values back into the quadratic formula:
[tex]\[ j = \frac{-3 \pm 73}{2} \][/tex]

This results in two potential solutions:
[tex]\[ j = \frac{-3 + 73}{2} = \frac{70}{2} = 35 \][/tex]
[tex]\[ j = \frac{-3 - 73}{2} = \frac{-76}{2} = -38 \][/tex]

Since ages cannot be negative, discard the negative solution. Therefore, Jon's age is:

[tex]\[ j = 35 \][/tex]

So the value of [tex]\( j \)[/tex] could be Jon's age is:

[tex]\[ \boxed{35} \][/tex]

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