Answer:
C and b
Explanation:
First question:
The polynomial expression we want to factor is x^2-5x-6
Let's calculate the discriminant to find the roots. The discrminant is b^2-4ac
● b= -5
● a = 1
● c = -6
b^2-4ac= (-5)^2-4*1*(-6) = 25+24 = 49>0
So this polynomial expression has two roots since the discriminant is positive
Let x" and x' be the roots:
● x'= (-b-7)/2a = (5-7)/2= -1
● x"= (-b+7)/2a = (5+7)/2 =6
7 is the root square of the discrminant
The factorization of this pulynomial is:
● a(x - x') (x-x")
● 1*(x-(-1)) (x-6)
● (x+1)(x-6)
So the right answer is c
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Second question:
The expression is: (-20*p^(-5)*q*r^(6))/(16*p^(-2)*q^(-3)*r^3)
To make it easier we will simplify the similar terms one by one.
● Constant terms
-20/16 = (-5*4)/(4*4) = -5/4
● terms containing p
-p^(-5)/p^(-2) = p^(-5-(-2)) = p^(-3) =1/p^3
● terms containg q
q/q^(-3)= q(1-(-3)) = q^4
● terms containg r
r^6/r^4 = r^(6-4) = r^2
Multiply all terms together:
● -5/4 *1/p^3 *q^4 *r^2
● (-5*q^4*r^2)/(4p^3)
The right answer is b