Answer:
y = 4·4^x
Step-by-step explanation:
We can write the exponential function in the form ...
y = a·b^x
The y-value for x=0 is 4, so that is the multiplier 'a' in our equation.
The ratio of values between x=1 and x=0 is 16/4 = 4, so that is the value of 'b' in the equation. The equation is ...
y = 4·4^x
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<em>Additional comment</em>
This could also be written ...
y = 4^(x+1)
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Consider the values for x=0 and x=1.
x=0: y = a·b^0 = a
x=1: y = a·b^1 = ab
Then the ratio of values is (ab)/(a) = b.
This is the fact that we used in the above working.
Let's see first x-y=-3. You can find x and x=-3+y
Then you replace x in x+3y=5
-3+y+3y=5
4y=8
y=2 But you have to find x too.
x=-3+2 x=-1
The answers are x=-1, y=2
One. that is the definition of a line.
Through any two points, there is exactly one line.
Would you not just multiply all of the following numbers to get a total of 160?
Y varies with x² times a constant. We will call the constant a
144=ax²
144 = a(4²)
144 = 16a
a = 9
Apply our equation y = 9x²
y = 9(-5)²
y = 9* 25
y=225
Answer is B