Answer: option d.
Step-by-step explanation:
If <em>y </em>varies directly as <em>x</em> and <em>z</em>, the form of the equation is:

Where<em> k</em> is the constant of variation.
If y=4 when x=6 and z=1 then substitute these values into the expression and solve for <em>k:</em>

<em> </em>Substitute the value of <em>k</em> into the expression. Then, the equation is:

To find the value of <em>y </em>when x=7 and z=4, you must substute these values into the equation. Therefore you obtain:


<em> </em>
The answer is -6x^2 + 7x, or answer choice A.
Answer:
rounded to the nearest 10: 680
rounded to the nearest 100: 700
Step-by-step explanation:
9 rounds up to 10 so it would go to 80
and 6 rounds up to 10 also so it goes to 700
brainilest maybe?
Answer:
If AB is a tangent to the circle, the triangle ABO is right angled, as the angle where a tangent meets the circumference is always 90 degrees.
We also know that Pythogoras' theorem only holds for right angled triangles.
The hypotenuse is 12 + 8 as 12 is the radius so is 20.
16^2+12^2 = 256 + 144 = 400 = 20^2 so AB must be tangent.