Solve the Triangle Equation: x with Constraint x > 0

Question

Find x.
x>0

xxxx+7x+7x+7131313

Video Solution

Solution Steps

00:00 Find X
00:03 Use the Pythagorean theorem in the triangle
00:06 Substitute appropriate values and solve for X
00:11 Expand brackets correctly
00:21 Collect terms and arrange the equation
00:47 Find the possible solutions for X
00:55 X must be greater than 0, therefore this solution is not logical
00:59 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we'll use the Pythagorean Theorem to establish a relationship between the sides of the right triangle:

Given:

  • One side a=x a = x
  • Another side b=x+7 b = x + 7
  • The hypotenuse c=13 c = 13

According to the Pythagorean Theorem:

a2+b2=c2 a^2 + b^2 = c^2

Substitute the given values:

x2+(x+7)2=132 x^2 + (x + 7)^2 = 13^2

Expand and simplify:\

x2+(x2+14x+49)=169 x^2 + (x^2 + 14x + 49) = 169

2x2+14x+49=169 2x^2 + 14x + 49 = 169

Subtract 169 from both sides to set the equation to 0:

2x2+14x+49169=0 2x^2 + 14x + 49 - 169 = 0

2x2+14x120=0 2x^2 + 14x - 120 = 0

Divide the entire equation by 2 to simplify:

x2+7x60=0 x^2 + 7x - 60 = 0

We now have a quadratic equation that can be factored as:

(x+12)(x5)=0 (x + 12)(x - 5) = 0

Set each factor equal to 0 and solve for x x :

  • x+12=0 x + 12 = 0 gives x=12 x = -12
  • x5=0 x - 5 = 0 gives x=5 x = 5

Since x>0 x > 0 , we have x=5 x = 5 .

Therefore, the solution to the problem is x=5 x = 5 .

Answer

x=5 x=5