Amanda Billy
1st week 10 5
2nd week 20 10
3rd week 30 20
4th week 40 40
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A) Amanda's method is linear because the number of minutes increased by an equal number every week.</span>
common difference is 10.
1st week 0 + 10 = 10
2nd week 10 + 10 = 20
3rd week 20 + 10 = 30
4th week 30 + 10 = 40
Billy's method is exponential:
5(2)^x
1st week 5(2⁰) = 5(1) = 5
2nd week 5(2¹) = 5(2) = 10
3rd week 5(2²) = 5(4) = 20
4th week 5(2³) = 5(8) = 40
With what? what’s the question
Answer: The options are kinda weird
But the solution to x - 12.5 = 17 is x = 29.5, so whichever equation you plug this into is correct is the right equation...
Answer:
Step-by-step explanation:
Let 
Subbing in:

a = 9, b = -2, c = -7
The product of a and c is the aboslute value of -63, so a*c = 63. We need 2 factors of 63 that will add to give us -2. The factors of 63 are {1, 63}, (3, 21}, {7, 9}. It looks like the combination of -9 and +7 will work because -9 + 7 = -2. Plug in accordingly:

Group together in groups of 2:

Now factor out what's common within each set of parenthesis:

We know this combination "works" because the terms inside the parenthesis are identical. We can now factor those out and what's left goes together in another set of parenthesis:

Remember that 
so we sub back in and continue to factor. This was originally a fourth degree polynomial; that means we have 4 solutions.

The first two solutions are found withing the first set of parenthesis and the second two are found in other set of parenthesis. Factoring
gives us that x = 1 and -1. The other set is a bit more tricky. If
then
and

You cannot take the square root of a negative number without allowing for the imaginary component, i, so we do that:
±
which will simplify down to
±
Those are the 4 solutions to the quartic equation.