Answer:
True
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
Here (h, k) = (- 4, - 9), thus
y = a(x + 4)² - 9
To find a substitute the coordinates of the zero (- 7, 0) into the equation.
0 = a(- 7 + 4)² - 9, that is
0 = 9a - 9 ( add 9 to both sides )
9a = 9 ( divide both sides by 9 )
a = 1, thus
y = (x + 4)² - 9 ← expand factor using FOIL
y = x² + 8x + 16 - 9
y = x² + 8x + 7
Answer:
The domain is the number of gallons and the range is the distance traveled.
Since the car can travel 30 miles one gallon of gas, we multiply by 12 to get the distance the car can travel in 12 gallons of gas.
A line that passes through an angle and splits it into two equal adjacent angles
Number of weekend minutes used: x
Number of weekday minutes used: y
This month Nick was billed for 643 minutes:
(1) x+y=643
The charge for these minutes was $35.44
Telephone company charges $0.04 per minute for weekend calls (x)
and $0.08 per minute for calls made on weekdays (y)
(2) 0.04x+0.08y=35.44
We have a system of 2 equations and 2 unkowns:
(1) x+y=643
(2) 0.04x+0.08y=35.44
Using the method of substitution
Isolating x from the first equation:
(1) x+y-y=643-y
(3) x=643-y
Replacing x by 643-y in the second equation
(2) 0.04x+0.08y=35.44
0.04(643-y)+0.08y=35.44
25.72-0.04y+0.08y=35.44
0.04y+25.72=35.44
Solving for y:
0.04y+25.72-25.72=35.44-25.72
0.04y=9.72
Dividing both sides of the equation by 0.04:
0.04y/0.04=9.72/0.04
y=243
Replacing y by 243 in the equation (3)
(3) x=643-y
x=643-243
x=400
Answers:
The number of weekends minutes used was 400
The number of weekdays minutes used was 243
Answer:
All expressions are correct
Step-by-step explanation:
9z+7z = 16 z
We need to find an expression ( or expressions ) that are equal to 16z
6z+3z+ 7z = 16z Correct
z+8z+7z = 16z Correct
z*16 = 16z Correct
21z+ -5z = 16z Correct