Question

Evaluate (2-5i) (p+q) (i) when P=2 and q=5i

Answer 1

Answer:

Step-by-step explanation:

(2-5i)(2+5i)

(2)²-(5i)²

4-25i²

-25i²+4

Answer 2

Answer:

$(2-5i)(p+q)=29$

Step-by-step explanation:              

Given : Expression $(2-5i) (p+q)$

To find : Evaluate when p=2 and q=5i ?

Solution :

Write the expression,

$(2-5i)(p+q)$

Substitute, p=2 and q=5i

$(2-5i)(p+q)=(2-5i)(2+5i)$

We know, $(a+b)(a-b)=a^2-b^2$

$(2-5i)(p+q)=2^2-(5i)^2$

$(2-5i)(p+q)=4-25i^2$

$(2-5i)(p+q)=4-25(-1)$

$(2-5i)(p+q)=4+25$

$(2-5i)(p+q)=29$