The function of h can be written as h(x) = -3x + 5
To find this function, we first have to note the two ordered pairs given to us. Since h(4) = -7, we know that when we use x = 4 in the equation, we get that the function equals -7. Therefore, we have an ordered pair of (4, -7). If we do the same for the second set of data, we have the ordered pair of (-1, 8).
Now we can use these two ordered pairs to find the slope of the equation using the slope formula.
m (slope) = (y2 - y1)/(x2 - x1)
m = (8 - -7)/(-1 - 4)
m = 15/-5
m = -3
Now that we have the slope, we can use that and a point of our choosing to find the intercept. Just use slope intercept form.
y = mx + b
8 = -3(-1) + b
8 = 3 + b
5 = b
Now that we have slope and intercept, we can write the equation as:
h(x) = -3x + 5
From here we can find h(8) by inputting 8 in for x.
h(8) = -3(8) + 5
h(8) = -24 + 5
h(8) = -19