Show all steps Find the value of y fora given value of x if y varies directly with x
If y =-252 when x=84, what is y when x=74?
y = k x
-252 = k (84)
k = -252/84 = -3
y = -3 (74)
y = - 222
Tysm Damon!
To find the value of y when x = 74, we can use the concept of direct variation. In direct variation, two variables are directly proportional to each other, meaning they increase or decrease at the same rate.
Let's start by determining the constant of variation, denoted by k. The formula for direct variation is y = kx.
Step 1: Find the value of k.
We are given that when x = 84, y = -252. Substitute these values into the direct variation formula and solve for k:
-252 = k * 84
Divide both sides of the equation by 84 to isolate k:
k = -252 / 84
k = -3
Step 2: Use the value of k to find y when x = 74.
Now that we know the value of k, substitute it into the direct variation formula along with x = 74 to find y:
y = k * x
y = -3 * 74
y = -222
Therefore, when x = 74, y = -222.
To find the value of y when x = 74, we can use the concept of direct variation.
In direct variation, y is directly proportional to x, which means that if x increases, y will also increase and if x decreases, y will also decrease. Mathematically, we can represent direct variation as:
y = kx
where k is the constant of variation.
To find the value of y, we need to determine the value of k.
Given that when x = 84, y = -252, we can substitute these values into the equation to solve for k:
-252 = k * 84
Divide both sides of the equation by 84:
-252/84 = k
Simplifying further, we find that:
k = -3
Now that we know the value of k, we can substitute it back into the equation:
y = -3x
To find the value of y when x = 74, we can plug in x = 74 into the equation:
y = -3 * 74
Calculating this expression, we find that:
y = -222
Therefore, when x = 74, y = -222.