The cost of a computer processor is directly proportional to its speed. A 4GHz processor costs £400.

Let
x
be the speed of a processor in GHz.

Let
y
be the cost of a process in pounds.

Find a formula linking the two variables.

Write the component forms of vectors u and v, shown in the graph, and find v − 2u. u= (< -3, -2> , < -3, -1> , < -2, -2> , < -2, -1> ) v= (< -5, 1> , -4, 0> , < 0, -4> , < 1, -5> ) v-2u= (< 5, 3> , < 0, 4> , < 4, 0> , < 5, -3>