With u = <-7, 6> and v = <-4, 17>, we have
u + 3v = <-7, 6> + 3 <-4, 17> = <-7, 6> + <-12, 51> = <-19, 57>
We want to find a vector w such that
u + 3v + w = <1, 0>
Subtract u + 3v from both sides to get
w = <1, 0> - (u + 3v) = <1, 0> - <-19, 57>
w = <20, -57>