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

[tex]\( j = \square \)[/tex]



Answer :

Sure, let's work through the problem step by step to find Jon's age.

1. Define Variables:
- Let [tex]\( j \)[/tex] represent Jon's age.
- Since Laura is 3 years older than Jon, Laura's age is [tex]\( j + 3 \)[/tex].

2. Set Up the Equation:
- According to the problem, the product of their ages is 1330. Therefore, we can write the equation:
[tex]\[ j \times (j + 3) = 1330 \][/tex]

3. Solve the Equation:
- We need to solve the quadratic equation:
[tex]\[ j^2 + 3j - 1330 = 0 \][/tex]

- To solve this quadratic equation, we can use 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].

- Plugging in the values we get:
[tex]\[ j = \frac{{-3 \pm \sqrt{{3^2 - 4 \cdot 1 \cdot (-1330)}}}}{2 \cdot 1} \][/tex]
[tex]\[ j = \frac{{-3 \pm \sqrt{{9 + 5320}}}}{2} \][/tex]
[tex]\[ j = \frac{{-3 \pm \sqrt{{5329}}}}{2} \][/tex]

- The square root of 5329 is 73, so:
[tex]\[ j = \frac{{-3 \pm 73}}{2} \][/tex]

- This leads to two possible solutions:
[tex]\[ j = \frac{{-3 + 73}}{2} = \frac{70}{2} = 35 \][/tex]
[tex]\[ j = \frac{{-3 - 73}}{2} = \frac{-76}{2} = -38 \][/tex]

4. Determine the Reasonable Solution:
- Jon's age must be a non-negative number. Therefore, the negative solution of [tex]\( -38 \)[/tex] is not reasonable in this context.

- Thus, the only feasible solution is:
[tex]\[ j = 35 \][/tex]

So, Jon's age is [tex]\( \boxed{35} \)[/tex].