3. solve the system of equations by substitution.

x= -4y
x+5y=2

a. (-8,2)
b. (8,-2)
c. (2/9,-8/9)
d. (-12,3)

4. solve the system of equations by elimination.

3x+4y=31
2x-4y=-6

a. (4,5)
b. (5,4)
c. (-5,12.5)
d. (5,-4)

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.