Answer: x = 20
Step-by-step explanation:
So the figures are the same, except the bigger one is bigger. It's equally bigger on all sides, so basically 6 * y = 15 to find what it is enlarged by. Then multiple 8 by y to find the missing length.
6*y = 15
/6
y = 2.5
8 * 2.5 = 20
We can also check this by:
4 * 2.5 = 10
6 * 2.5 = 15
8 * 2.5 = 20
