Answer:
Step-by-step explanation:
x= money earned per hour working as a cashier.
y=money earned per hour working delivering newspapers.
We propose the following system of equations:
5x + 4y =77
6x + 3y=78
We solve the system by reduction method:
-6*(5x+4y=77) ⇒ -30x-24y=-462
5*(6x+3y=78)⇒ 30x+15y=390
---------------------------
-9y=-72 ⇒ y=-72 /-9=8
Now, we get the value of "x" replacing the value of "y" by "8" in any part of the equation above.
5x + 4(8)=77
5x+32=77
5x=77-32
5x=45
x=45/5=9
therefore;
money earned per hour working as a cashier= $9/ hour
money earned per hour working delivering newspapers=$8/hour
Answer: 0.12
Step-by-step explanation:
There are 65 candy bars. Out of that;
2 candy bars have 300 to 350 calories
1 candy bar has 350 to 400 calories
4 candy bars have 400 to 450 calories
1 candy bar has 450 to 500 calories
The total proportion out of 65 candy bars that have over 300 calories is;
= ( 2 + 1 + 4 + 1) / 65
= 8/65
= 0.12
Since the parabola passes by the center its equation is:
y = ax². But it opens downward, that means the coefficient a is negative.
Then the equation becomes:
y = - ax², with x = 0 as its axis of symmetry.
We are given that the height is 84 ft when the opening downward is 42 ft.
That means to the (height) y, corresponds x =+21 & x=-21 (due to symmetry).
In order to calculate a let's plug y & x with their related values:
y = - ax²
84 = - a(21)²
84 = - a(441) and a = - 84/441 ↔ a = - 4/21
And the final equation is : y = -4/21. x²
114/6=9 parts per minute. 9 parts * 15 minutes= 135 parts
Answer:
f(x + 1) = 3x² + 5x + 7
Step-by-step explanation:
To find f(x + 1), substitute x = x + 1 into f(x), that is
f(x + 1) = 3(x + 1)² - (x + 1) + 5 ← expand (x + 1)² using FOIL
= 3(x² + 2x + 1) - x - 1 + 5 ← distribute parenthesis by 3
= 3x² + 6x + 3 - x - 1 + 5 ← collect like terms
= 3x² + 5x + 7
