Answer:
$6
Step-by-step explanation:
$39.84≈$40
tip=15% of 40=0.15×40=$6.00
Answer:
398-cent stamp for postage.
Step-by-step explanation:
For one letter, Travis needs 37-cent stamp
For four letters, Travis needs 37-cent stamp x 4 letters
= 148-cent
Again,
For one postcard, he needs 25-cent stamp
For ten postcards, he needs 25-cent stamp x 10 postcards
= 250-cent
Therefore, he will spend = (148-cent + 250-cent) = 398-cent stamp for postage.
ax² + bx + c = 0
x = (-b ± √(b² - 4ac))/2a
First, rewrite the first equation so that the first coefficient is 1. Divide everything by a.
(ax² + bx + c = 0)/a =
x² + (b/a)x + (c/a) = 0
Isolate (c/a) by subtracting (c/a) from both sides
x² + (b/a)x + (c/a) (-(c/a) = 0 (- (c/a)
x² + (b/a)x = 0 - (c/a)
Add spaces
x² + (b/a)x = -c/a
Take 1/2 of the middle term's coefficient and square it. Remember that what you add to one side, you add to the other.
x² + (b/a)x + (b/2a)² = -c/a + (b/2a)²
Simplify the left side of the equation.
x² + (b/a)x + (b/2a)² = (x + (b/2a))²
(x + b/2a))² = ((b²/4a²) - (4ac/4a²)) -> ((b² - 4ac)/(4a²))
Take the square root of both sides of the equation
√(x + b/2a))² = √((b²/4a²) - (4ac/4a²))
x + b/(2a) = (±√(b² - 4ac)/2a
Simplify. Isolate the x.
x = -(b/2a) ± (∛b² - 4ac)/2a = (-b ± √(b² - 4ac))/2a
~
Using a linear function, it is found that the product rs is rs = 81.
<h3>What is a linear function?</h3>
A linear function is modeled by:
y = mx + b
In which:
- m is the slope, which is the rate of change, that is, by how much y changes when x changes by 1.
- b is the y-intercept, which is the value of y when x = 0, and can also be interpreted as the initial value of the function.
In this problem, when x changes by 68(from -64 to 68), y changes by -16(from 12 to -4), hence the slope is given by:
m = -16/64 = -0.25.
Hence:
y = -0.25x + b.
When x = 34, y = -4, hence this is used to find b.
-4 = -0.25(34) + b
b = 4.5.
Hence the function is:
y = -0.25x + 4.5.
f(r) = 0, hence:
-0.25x + 4.5 = 0
x = 4.5/0.25
x = 18
r = 18.
f (0) = s, hence s = 4.5.
Then the value of the product is:
rs = 18 x 4.5 = 81.
More can be learned about linear functions at brainly.com/question/24808124
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Answer:
I think the answer is B
Step-by-step explanation:
