Answer:
53
Step-by-step explanation:
You want the value of a^2 +b^2, given that 'a' and 'b' are roots of the polynomial x^2 +7x -2.
Factors
If the roots are 'a' and 'b', then the factored form is ...
(x -a)(x -b) = x^2 -(a+b)x +ab
Comparing this to the given polynomial, we see that ...
-(a+b) = 7
ab = -2
Desired expression
The expression a^2 +b^2 can be written as the sum ...
a^2 +b^2 = a^2 +2ab +b^2 -2ab = (a+b)^2 -2ab
Using the values of (a+b) and ab from above, we see that ...
a^2 +b^2 = (-7)^2 -2(-2) = 49 +4 = 53
The given expression has a value of 53.
