PLZ HELP QUIK PLZ HELP PLZ

(x,y) = (-2,7)

Step-by-step explanation:

7x+2y=0

9x+4y=10

y = -9x/4 + 5/2

7x+2 (-9x/4 + 5/2) = 0

5x/2 = -5

5x = -10

x = -2

use x and substitute to get y

y = -(9/4) (-2) +5/2 = 7

it costs $20 to interview each person for a survey. find the cost to obtain a +- 3% margin of error.

step-by-step explanation:

copy and paste, put it in google

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step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.