4. which of these are solutions to the following system of equations?
x - 2y = 7
13x + 7y = 8
a. (7,0)
b. (5, -1)
d. (-2,2)
c. (3, -2)

Step-by-step explanation:

We have to check each one answer in the following system:

x - 2y = 7

13x + 7y = 8

a. (7,0)

7 - 2.0 = 7 (it's true)

13.7 + 7. 0 = 8 (it's false)

It isn't a correct answer.

b. (5, -1)

5 - 2.(-1) = 7 (correct)

13.5 + 7 (-1) = 8 (wrong)

It isn't a correct answer.

c. (-2,2)

-2 - 2.2 = 7 (wrong)

d. (3, -2)

3 - 2. (-2) = 7 (correct)

13.(3) + 7.(-2) = 8 (wrong)

So, none of them is answer.

rick would give her the best deal as he will charge $8.88 per hour

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