En una granja hoy gallinas y cerdos al contar las cabezas de ios animales hay 50 y al contar las patas hay i34 "x" representa el nümero de gallinas "y" representa el número de cerdos la solución al sistema de ecuaciones lineales para conocer el número de animales es

3 (a) A car travels at \( 20 \mathrm{~m} / \mathrm{s} \). The mass of the car is 1500 kg . (i) State the equation linking momentum, mass and velocity. (ii) Calculate the momentum of the car.

If \( n \) is the largest integer for which \( n^{200}<5^{300} \), determine the value of \( n \).

7. You have a 56 g sample of iron(II)sulphide? (a) How many moles of FeS are there in the sample? (b) How many molecules of FeS are there in the sample?

20. Express \( \frac{39}{4-\sqrt{3}} \) in the form \( a+b \sqrt{3} \), where \( a \) and \( b \) are integers Show clear working out.

(1) \( 5 a^{6} b^{7} \div 10 a^{3} b^{5} \)