Question

URGENT PLEASE HELP!!!!!

1. Which best describes the equation y/6=x?
A. The relationship shows an inverse variation with a constant of variation of -6
B. The relationship shows an inverse variation with a constant of variation of -1/6
C. The relationship shows an inverse variation with a constant of variation of 1/6
D. The relationship does not show an inverse variation.

2. If y varies inversely with x and y=5 when x=2.5, what is the value of y when x=20?
A. 0.1
B. 0.625
C. 0.3125
D. 1.6

3. The current, I, in a circuit varies inversely with the resistance, R. If the resistance is 12 when the current is 3, what is the resistance when the current is 6?
A. 1/6
B. 1.5
C. 6
D. 24

Answer 1

(1)

we are given

$\frac{y}{6} =x$

we can  find for y

multiply both sides by 6

$\frac{y}{6}*6 =6*x$

$y=6x$

we can see that y is directly proportional to x

so, option-D........Answer

(2)

y varies inversely with x

so, we can write it as

$y=k\frac{1}{x}$

now, we are given

y=5 when x=2.5

so, we can plug it here

$5=k\frac{1}{2.5}$

and then we can solve for k

$5*2.5=2.5*k\frac{1}{2.5}$

$k=12.5$

now, we can plug back

$y=\frac{12.5}{x}$

we can plug x=20

$y=\frac{12.5}{20}$

$y=0.625$.............Answer

(3)

we are given

The current, I, in a circuit varies inversely with the resistance, R

so, we can write it as

$I=\frac{k}{R}$

we have R=12 when I=3

so, we can plug it

$3=\frac{k}{12}$

now, we can solve for k

$3*12=12*\frac{k}{12}$

$k=36$

now, we can plug back

$I=\frac{36}{R}$

we can plug R=6

$I=\frac{36}{6}$

$I=6$................Answer