round to the neatest whole number

Choose the graph that matches the following system of equations: 7x + 2y = −6 6x − 7y = 21 a line includes points negative 2 comma 4 and 0 comma negative 3. a line includes points 6 comma 2 and 0 comma negative 3 a line includes points 0 comma negative 3 and 6 comma 2. a line includes points negative 2 comma 1 and negative 3 comma 4 a line includes points 0 comma negative 3 and negative 1 comma 4. a line includes points 0 comma negative 3 and negative 1 comma 3 a line includes points 0 comma 3 and negative 1 comma negative 3. a line includes points 0 comma negative 3 and negative 2 comma 4.

This is so hard and it’s for a test

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.