Answer:
x = 9
Step-by-step explanation:
Make 2 fractions, one for each triangle:
25 / 4x - 1 = 10 / x + 5
Cross multiply the denominator of one x the numerator of the other
25 (x + 5) = 10 (4x - 1)
Use the distributive property
25x + 125 = 40 x - 10
Subtract 25x from each side
125 = 15x - 10
Add 10 to each side
135 = 15x
Divide each side by 15
x = 9
