more functions

[kkiceman14]

HOw do i start this problem?



let h(x)=12-3x. Determine all values of x so that h(2x)>24

 

[Unco]

Write down what h(2x) is by substituting 2x for x in h(x). Make it bigger than 24.

 

[kkiceman14]

make what bigger than 24?
SO should it look like this
h(x)=12-3(2x)

 

[kkiceman14]

make what bigger than 24?
SO should it look like this
h(2x)=12-3(2x)

 

[Unco]

Absolutely. Expand the parentheses and you have

h(2x) = 12 - 6x

h(2x) is to be greater than 24.

12 - 6x > 24

Can you take it from there?

 

[kkiceman14]

i have another question

it is

let f(x,y)=x+2y+6. Find the value(s) of a so that f(6,a) - f(a,6)=f(a,a)

 

[Unco]

This is not much different than the previous problem.

f(6,a) just means substitute x=6 and y=6 into f(x,y):

f(6,a) = 6 + 2a + 6

Do the same for the other two. You have an equation to solve for a.