Question

Which values of p and q would make the value of the following expression equal to 58i? (3 – 7i)(p + qi)i

Answer 1

Answer:

For short the answer is A.      p = 3 , q = 7

Answer 2

we are given

$(3-7i)(p+qi)i=58i$

firstly, we will simplify left side

and then we can compare it with right side

so, we can distribute

$(3p+3qi-7pi-7qi^2)i=58i$

$(3p+3qi-7pi+7q)i=58i$

we have i on both sides

so,i will get cancelled

$(3p+3qi-7pi+7q)=58$

$(3p+7q+(3q-7p)i)=58$

we can also write as

$(3p+7q)+(3q-7p)i=58+0*i$

now, we can compare

and we get

$3p+7q=58$

$3q-7p=0$

now, we can solve for p and q

we get

$q=7,\:p=3$.............Answer