Question

If f(x)= 5x+40 what is f(x) when x =-5

Answer 1

If f(x)= 5x+40 what is f(x) when x =-5

---f(x)= 15

Answer 2

Answer:

f(-5) = 15

Step-by-step explanation:

f(x) is a straight line with a y-intercept of f(0) = y = 40 and a x-intercept of x = -40/5 = -8.

With x = -5 and substituting it into f(x) the following occurs:

f(-5) = 5×(-5) + 40 = -25 +40 = 15

∴ When x=-5, y will be 15 and the new coordinates will be a point on the like with (-5, 15).

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