Question

If $(a+b)-i(3a+2b)=5+2i$, then find $a$ and $b$.

• A. $a=12$, $b=17$
• B. $a=12$, $b=-17$
• C. $a=-12$, $b=-17$
• D. $a=-12$, $b=17$

Answer 1

The correct option is D $a=-12$, $b=17$

We have,
$(a+b)-i(3a+2b)=5+2i$
$\Rightarrow a+b=5$ and $-(3a+2b)=2$
$\Rightarrow a=-12$ and $b=17$
Ans: D