If p + q = 10 and pq = 5 then find the value of p/q + q/p
A22
B20
C18
D16
Answer:
C. 18
Read Explanation:
The expression becomes: (p × p) / (q × p) + (q × q) / (p × q) = (p2 + q2) / pq.
We are given p + q = 10 and pq = 5.
Find p2 + q2:. Recall the algebraic identity for squaring a binomial: (a + b)2 = a2 + b2 + 2ab.
Applying this to our problem: (p + q)2 = p2 + q2 + 2pq.
We want to find p2 + q2, so rearrange the identity: p2 + q2 = (p + q)2 - 2pq.
Now, substitute the given values: p2 + q2 = (10)2 - 2(5).
Calculate the values: p2 + q2 = 100 - 10 = 90.
Substitute Back into the Simplified Expression: Now we have all the components for (p2 + q2) / pq.
Substitute the calculated values: 90 / 5.
Perform the division: 90 / 5 = 18.