(12^2 divided by 6) divided by 2 . 1^2

7x+8y=-18, 4x-9y=-3 solve the system of equations

What is the 12th term of b(n)=-4-2(n-1)

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.