Determine if the matrix below is invertible. use as few calculations as possible. justify your answer. [3 0 -4] [2 0 6] [-3 0 8]choose the correct answer below. (a) the matrix is invertible. the columns of the given matrix span r^3.(b) the matrix is not invertible. if the given matrix is a, the columns of a do not form a linearly independent set.(c) the matrix is invertible. the given matrix has 2 pivot positions.(d) the matrix is not invertible. if the given matrix is a, the equation ax = 0 has only the trivial solution.

the equation cos(35) =a/25 can be used to find the length of bc what is the length of bc? round to the nearest tenth

step-by-step explanation:

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240