The correct answer is 34.034567.... Hope this helps.
-8 + 7y = - 18
7y =10
y =10/7
Substitute y = 10/7 into first equation
4x - 7 (10/7)=2
4x - 10 =2
4x = 12
x = 3
Thus, the solution is x = 3 and y = 10/7
The area of the circle is 452.16
The Greatest Common Factor: G C F ( 45, 90 , 75 ) = 15
The greatest number of stones Marco can make is 15.
45 : 15 = 3
90 : 15 = 6
75 : 15 = 5
He will use: 3 red, 6 blue and 5 yellow tiles in each stone.