It cost Naomi $7.70 to send 154 text messages. How many text messages did she send if she spent $5.25?

You have to find the unit rate

SO..

7.70 / 154 = 0.05

So it cost her 0.05 cents for each text.

So then you divide $ 5.25 by the unit rate to get the number of text

5.25 /0.05 = 105

so she sent 105 text

To check it you just multiply the unit rate by the number of text you got and you show come up with $ 5.25

0.05 x 105 = 5.25

8(-10x+3.5y-7)

8×-10x + 8×3.5y + 8×-7

-80x + 28y - 56

therefore

-80x+28y-56 is the correct answer

correct answer:

b.(19,-2)