Question

Write an expansion of the vector x in the given vectors p, q and r.
x={-2,0,9}, p={0,-1,2}, q={1,0,-1}, r={-1,2,4}

Answer 1

Could you be a bit more specific as to what your question is? I'm not sure what it means to expand a vector in vectors.

Answer 2

It should be expression

Answer 3

Let a be the number of vector p's you need, let b be the number of vector q's you need, and let r be the number of vector r's you need.

Then,
x1 = a*(p1) + b*(q1) + c*(r1)
x2 = a*(p2) + b*(q2) + c*(r2)
x3 = a*(p3) + b*(q3) + c*(r3)

solve the system