Question

encontrar valor de x ​

Answer 1

Recordemos el teorema de Thales que dice:

$\overline{ \frac{AC}{CE} } \: = \: \overline{\frac{BD}{DF} }$

Figura 1.

• 6 / 8 = x / 5
• 3 / 4 = x / 5
• 15 = 4x
• 4x = 15
• x = 15 / 4
• x = 3,75

Figura 2.

• 4x + 1 / x + 2 = 16 / 18
• 4x + 1 / x + 2 = 9 / 8
• 9(4x + 1) = 8(x + 2)
• 36x + 9 = 8x + 16
• 36x - 8x = 16 - 9
• 28x = 7
• x = 1 / 4
• x = 0,25

Figura 3.

• x + 2 / 2x - 1 = 6 / 8
• x + 2 / 2x - 1 = 3 / 4
• 4(x + 2) = 3(2x - 1)
• 4x + 8 = 6x - 3
• 4x - 6x = -3 - 8
• -2x = -11
• x = 11 / 2
• x = 5,5