Answer:
Explanation:
1)If y=4 when x=-2. Find x when y=-5
This is assumed to be a direct proportion. It means that x is directly proportional to y. To make x to be equal to y, that is, removing the "proportionality" sign and replacing it with the "equal to" sign, we will introduce a proportionality constant, k. Therefore,
x = ky - - - - - - - 1
Therefore, we would find the value of k. From the information given,
y=4 when x= -2. Therefore, we will substitute y= 4 and x = -2 in equation 1
-2 = 4k
k = -2/4 = -1/2
x = -1/2 × y = -y/2 - - - - - - - -2
We want to find x when y=-5
Substituting y= -5 in equation 2,
x = - -5/2 = 15/2
2) If y=20 when x=-5. Find x when y= -1
We would follow same procedure above.
x = ky - - - - - - - 1
Therefore, we would find the value of k. From the information given,
y=20 when x=-5. Therefore, we will substitute y= 20 and x = -5 in equation 1
-5 = 20k
k = -5/20= -1/4
x = -1/4 × y = -y/4 - - - - - - - -2
We want to find x when y=-5
Substituting y= -5 in equation 2,
x = - -5/4 = 5/4