Can someone help me with math I need help I will attempt to give y’all help too!

Answer:
x = 10
Step-by-step explanation:
"y" will be the number that increases the next shapes size to not be confused with "x"
7*y = 17.5
7 / 17.5 = 2.5
y = 2.5
now multiply 2.5 into 4
2.5 * 4 = 10
x = 10