Which of the following are possible ways to eliminate a variable by multiplying first?

−x + 4y = 5
9x − 3y = 21

a. multiply the first equation by 3 and the second equation by 4.
b. multiply the first equation by 4 and the second equation by 3.
c. multiply the first equation by 3 and the second equation by 9.
d. multiply the first equation by 9 and the second equation by 4.
e. multiply the second equation by 9.
f. multiply the first equation by 9.

A

Step-by-step explanation:

The answer is A nd i'm 100% sure

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950

17

step-by-step explanation:

51/3=17

thus 17 is your answer.