Answer:
x^2 + -2 sqrt(7) x + 7
Step-by-step explanation:
Expand the following:
(x - sqrt(7))^2
(x - sqrt(7)) (x - sqrt(7)) = (x) (x) + (x) (-sqrt(7)) + (-sqrt(7)) (x) + (-sqrt(7)) (-sqrt(7)):
x x - sqrt(7) x - sqrt(7) x - (-sqrt(7) sqrt(7))
(-1)^2 = 1:
x x - sqrt(7) x - sqrt(7) x + (sqrt(7))^2
x x = x^2:
x^2 - sqrt(7) x - sqrt(7) x + sqrt(7)^2
Cancel exponents. (sqrt(7))^2 = 7:
x^2 - sqrt(7) x - sqrt(7) x + 7
Combining like terms, sqrt(7) x (-1) + sqrt(7) x (-1) = -2 sqrt(7) x:
Answer: x^2 + -2 sqrt(7) x + 7