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]

step-by-step explanation:

if you want to solve percent error follow these steps.

1. subtract the accepted value from the experimental value.

2. take the absolute value of step 1.

3. divide that answer by the accepted value.

4. multiply that answer by 100 and add the % symbol to express the answer as a percentage.

if you want to solve percent of change just do this.

1. work out the difference (increase) between the two numbers you are comparing.

2. divide the increase by the original number and multiply the answer by 100. if your answer is a negative number then this is a percentage decrease.

hope this : )

stethere all not eveanp-by-step explanation: