$\bf \begin{array}{cccccclllll}
\textit{something}&&\textit{varies directly to}&&\textit{something else}\\ \quad \\
\textit{something}&=&{{ \textit{some value}}}&\cdot &\textit{something else}\\ \quad \\
y&=&{{ k}}&\cdot&x

&& y={{ k }}x
\end{array}
\\ \quad \\
\textit{we know that, when}
\begin{cases}
y=-3\\
x=5
\end{cases}\implies y=kx\implies (-3)=k(5)$

solve for "k", to find the "constant of variation",
then plug it back in the y = kx, to get the equation
now
what's is y when x = -1?
well, just plug that in the equation with the found "k" value,
to get "y" :)

3 0

3 years ago

Read 2 more answers

How many roots does the equation 3x² = 1 - 7x have and what is the nature of the roots

AnnyKZ [126]

Answer:

Step-by-step explanation:

Rewrite this quadratic in standard form: 3x^2 + 7x - 1.

The coefficients of x are {3, 7, -1}, and so the discriminant is b^2 - 4ac, or

7^2 - 4(3)(-1), or 49 + 12, or 61. Because the discriminant is positive, this quadratic has two real, unequal roots

7 0

3 years ago