Question

Given that y varies directly with x, use the values specified to write a

Answer 1

Answer:

(a)y=-10x

(b)x=0.9

Step-by-step explanation:

If y varies directly with x, we write:

$y \propto x\\y=kx where k is the constant of proportionality.\\If x = -19, y = 190\\190=-19k\\ Divide both sides by -19\\k=190 \div -19\\k=-10$

Therefore, a direct variation equation relating y to x is:

(a)y=-10x

(b)When y=-9

Substituting y=-9 into the equation obtained in (a) above

$-9=-10x\\ Divide both sides by -10 \\x=-9\div -10\\x=0.9\\ Therefore, when y=-9, x=0.9$