Recall that the characteristic polynomial of a 2x2 matrix

is

but

and

, so the characteristic polynomial for

is

We're given that the trace is 15 and determinant is 50, so the characteristic polynomial for the matrix in question is

and the eigenvalues are those

for which the characteristic polynomial evaluates to 0.
Answer:
Step-by-step explanation: FIRST YOU PUT THE NUMBER AND THEN X AFTER THAT YOU PUT THE NEXT NUMBER.
Using the general equation formula;
y-y1=m(x-x1)
y1=20 and x1=4
Since the two lines are perpendicular, they have the same gradients
But gradient for y=4x+5 is 4
Therefore m of the equation is 4
Substituting all this into the general formula;
y-20=4(x-4)
y-20=4x-16
y=4x-16+20
y=4x+4
The answer is 10/1
There are 10 boys and 1 of them is a sophomore