Simplification and solve using given condition

Write whether (2sqrt(45)+3sqrt(20))/(2sqrt(5)) on simplification gives a rational or an irrational number.

Use the graph given alongside, to find the co-ordinate of the point (s) satisfying the given condition: the ordinate is -4.

Use the graph given alongside, to find the co-ordinate of the point (s) satisfying the given condition: the ordinate is 3.

Use the graph given alongside, to find the co-ordinate of the point (s) satisfying the given condition: the abscissa is 2.

Use the graph given alongside, to find the co-ordinate of the point (s) satisfying the given condition: the ordinate is half of the abscissa.

Use the graph given alongside, to find the co-ordinate of the point (s) satisfying the given condition: the abscissa is equal to the ordinate.

Use the graph given alongside, to find the co-ordinate of the point (s) satisfying the given condition: the abscissa is 5.

Use the graph given alongside, to find the co-ordinate of the point (s) satisfying the given condition: the ordinate is 0.

Find the reading of the massless spring balance in the given condition

The persentage of ammonia produced from nitrogen and hydrogen under conditions of temperature and pressure is given in the graph Use the graph answering the following questions: What conditions of pressure produce the highest percentage of ammonia?