In the system below, what is the sum of the x-coordinates of all solutions? 7x^2+3y^2=187 3y^2-7x=47

The sum of the x-coordinates of all solutions is -2

Step-by-step explanation:

We are given system of equations as

Firstly, we will isolate x

now, we can plug back in first equation

now, we can solve for y

now, we can find x-values

At y=-5:

At y=5:

At y=-2:

At y=2:

now, we can add all x-coordinate solution values

So,

the sum of the x-coordinates of all solutions is -2

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

step-by-step explanation:

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