Evaluate each expression for the given value of the variable. 17. 4g-3;g=-2
18. 8p-12;p=4
19. 4x+8;x=-2
20. -5t-15;t=1
Pls help me I need this ASAP and show your work pls

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.