1.
(a) t^2 = -36
t = 6, -6
(b) x = 0, 7/2
© (2n+1)(n-4) = 0
n = 4, -1/2
(d) (k^2) - 4k - 21 = 0
(k+3)(k-7) = 0
k = 7, -3
2. x(x-7) = 30
(x^2) - 7x - 30 = 0
(x-10)(x+3) = 0
x = 10, -3
But -3 is impossible in this situation, as it would make both sides of the rectangle negative, so x = 10.