Answer:
Step-by-step explanation:
6) a) Cost = 12.40 x 0.6 = $7.44
b) Cost = 12.40 x 0.05 = $0.62
Y = 4x - 3
y = -x - 13
Since both equations equal y, we will just substitute both equations to equal each other.
4x - 3 = -x - 13
+x on both sides
5x - 3 = -13
+3 on both sides
5x = -10
/5 on both sides
x = -2
Substitute x = -2 into one of the equations.
y = -x - 13
y = -(-2) - 13
y = 2 - 13
y = -11
To check answer, plug in both x and y values into one of the equations.
y = -x -13
-11 = -(-2) - 13
-11 = 2 - 13
-11 = -11
Answer:
x = -2
y = -11
Let x be a variable, and f(x) a function of that variable.
f(2) is a <em>number </em>; it's the value of the function f(x) when x = 2, assuming that value exists.
f(x) = 2 is a <em>statement </em>; it says there is some value of x for which the function returns a value of 2. Because it's a statement, it can be true or false.
Here's an example:
Define f(x) = sin(x). Then f(2) = sin(2) ≈ 0.909297.
If x is a real number, then the statement sin(x) = 2 is false, because -1 ≤ sin(x) ≤ 1 for all real x.
If we replace 2 with 1, on the other hand, we get
f(1) = sin(1) ≈ 0.84147
and
sin(x) = 1 ==> x = π/2 + 2nπ
where n is any integer. (So we're talking about numbers like π/2, -3π/2, 5π/2, -7π/2, and so on.) We're saying here that any real number x of the above form satisfies the equation and makes the statement true.
John exercised 20% more than Toby. So the number of hours that John exercises per week is 14 + 0.2(14) = 14 + 2.8 = 16.8.
Jenny exercises two more hours than John. So the number of hours that Jenny exercises per week is 16.8 + 2 = 18.8.
So an expression representing the number of hours that Jenny exercises after w weeks is 18.8w.
Answer:
Step-by-step explanation:
