having trouble with polynomials

Question

Write the factored form of the polynomial function with real coefficients, a lead coefficient of 1, and zeros of , , , and .

Answer 1

(x+2)(x+1)(x-2)(x-1) = 0

or

(x^2-4)(x^2-1) = 0

or

x^4 -5x^2 + 4 = 0

just take each zero and change its sign, then add it to x, such as the zero 2 has the factor x-2

the zero -2 has the factor x--2 or x+2, zero 1 has factor x-1, zero -1 has the factor x--1 = x+2

multiply the 4 factors together and set them = 0