The set B = {v1, v2, v3, v4} is a basis of the vector space P3, polynomials

Question:

The set B = {v1, v2, v3, v4} is a basis of the vector space P3, polynomials with degree 3 or less. Therefore pB is a linear transformation, according to Theorem VRLT. Find a "formula" for pB. In other words, find an expression for pB(a + bx + cx2 + dx3).
v1 = 1 - 5x - 22x2 + 3x3
v2 = -2 + 11x + 49x2 - 8x3
v3 = -1 + 7x + 33x2 - 8x3
v4 = -1 + 4x + 16x2 + x3