If in the linear function y = KX + B, when x = 2, y = 3, every time x increases by one unit, the corresponding function value y increases by three units, the analytic expression of this linear function is

If in the linear function y = KX + B, when x = 2, y = 3, every time x increases by one unit, the corresponding function value y increases by three units, the analytic expression of this linear function is

Every time x increases by one unit, the corresponding function value y increases by three units
Then k = 3
y=3x＋b
Substituting x = 2, y = 3 into b = - 3
The analytic formula of a function is y = 3x-3

If in a function y = KX + 5, every time x increases by one unit, the corresponding function value decreases by three units, then the analytic expression of this function is?
It's best to write about the process

y=kx+5
y-3=k(x+1)+5
The two formulas can be obtained by subtracting
k=-3
So the analytic formula is y = - 3x + 5

If in a function y = KX-5, every time x increases by one unit, the corresponding function value decreases by three units, then the analytic expression of this function is

According to the meaning of the title
[k(x+1)-5]-(kx-5)=-3
kx+k-5-kx+5=3
k=3
So the analytic expression of this function is y = - 3x-5