The function is given by the formula y = 3x + 18. Determine: A) what is the value of y at x = -2.5
The function is given by the formula y = 3x + 18. Determine: A) what is the value of y at x = -2.5 B) at what value of x is the value of y -3 C) whether the graph of the function passes through point A (-5.3)
A) To determine the value of the function, we substitute the value of the argument into the equation of the graph:
y = 3 * (-2.5) + 18,
y = -7.5 + 18,
y = 10.5.
Answer: The value of the function is 10.5.
B) Let’s calculate what the value of the argument is, if it is known that the function takes the value -3 using substitution:
-3 = 3x + 18,
3x = -21,
x = -7.
Answer: the argument has a value of -7.
C) Substitute x = -5 into the equation and determine what y is equal to:
3 * (-5) + 18 = 3.
y = 3, the value is equal to the ordinate of point A.
Answer: yes, the graph goes through point A.