find the equation of the linear function f using the information f(4)=1 and f (8)=7?

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Look:
f(x)=ax+b
f(4)=1
4a+b=1


and f (8)=7
8a+b=7

{8a+b=7 -
{4a+b=1
---------------
4a=6
a=6/4
a=3/2

4a+b=1
4.3/2+b=1
6+b=1
b=1-6
b=-5

f(x)=3x/2-5
or
f(x)=(3x-10)/2...Show more

/first find the slope, which is 7/3 for this equation.

now set the equation equal to the slope.

7/3 = (y-8) / (x-7)
And solve it.

the equation would be:
y = 7/3*x - 25/3 or

f(x) = 7/3*x -25/3

Try by plotting x. you will get the results f(4) = and f(7) = 8...Show more