SOMEONE HELP ME ON THESE QUESTIONS

1.)  The sum(addition) of 21 and 5 times(multiplication) a number f is(=) 61.

f = unknown number/variable     [So 21 plus 5f(5 times f) equals 61]

21 + 5f = 61   [21(one-time) + 5f(number x variable) = 61(total)]

2.)  Seventeen more(addition) than seven times(multiplication) a number j is(=) 87.

j = unknown number/variable    [So 17 plus 7j(7 times j) equals 87]

17 + 7j = 87  

3.)   n = number of calls

18 + 0.05n = 50.50  

[Company charges $18 plus five cents per call(n), and the total charge was $50.50]

4.)     s = the number of students

40 + 30s = 220

[Tutor charges $40 plus $30 per student(s), and the total charge was $220]

-10i^2-4i

step-by-step explanation:

evaluate for p=2,q=5i

(2−4)(2+5i)i

(2−4)(2+5i)i

=−10i2−4i

idk

step-by-step explanation: