9514 1404 393
Answer:
triangle = 8
Explanation:
The right side can be factored so that you have ...
8 x 4 = (triangle x 7) - (triangle x 3)
8 x 4 = triangle x (7 - 3) . . . . use the distributive property
8 x 4 = triangle x 4 . . . . . . simplify
8 = triangle . . . . . . . . . . divide both sides by 4