to clean a tank 3/4 cup of this disinfector is needed for every 2 gallons of water. how many cup of disinfector are needed for 20 gallons of water ?​

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>