x is partly constant and partly varies as y when y=2, x=30 and when y=6, x=50. Find x when y=3
x = c + ky
when x=30, y=2 ----> 30 = c + 2k
when x=50, y=6 ----> 50 = c + 6k
solve these two equations for c and k, sub back into x = c + ky
then find x when y = 3
I suggest subtracting the two equation to solve for k
I don't get it
To find the value of x when y=3, we need to identify the relationship between x and y and use it to determine the solution.
Given that x is partly constant and partly varies as y, we can assume that there is a constant value of x when y remains the same and a linear relationship between x and y when y changes.
Let's first find the constant value of x when y=2 and y=6.
When y=2, x=30.
When y=6, x=50.
To find the constant value of x, we need to determine the difference in x-values for both y-values, which is:
Difference in x = x(y=6) - x(y=2) = 50 - 30 = 20.
So, when y changes by 4 units (from 2 to 6), x changes by 20 units.
To find the value of x when y=3, we need to determine how much x changes when y increases by 1 unit.
Since the difference in x for a change of 4 units in y is 20 units, the difference in x for a change of 1 unit in y is:
Difference in x = 20 / 4 = 5.
Therefore, when y increases by 1 unit, x increases by 5 units.
Since x=30 when y=2, and we need to find the value of x when y=3 (an increase of 1 unit), we can determine that:
x = 30 + (1 * 5) = 30 + 5 = 35.
Therefore, when y=3, x=35.