Answer:
56
Step-by-step explanation:
The easiest way to solve this is by cross multiplying. We can make an equation to find the answer of this by simply taking a side from each triangle and then the variable and equal side on the other triangle, shown below.
[tex]let \: \: ? = x[/tex]
[tex] \frac{7}{49} = \frac{8}{x} [/tex]
Now we solve with cross multiplication
[tex]7 x = 392 \\ x = 56[/tex]
Now we know the mystery number is 56
