Answer:
10
Step-by-step explanation:
Ground level is where h = 0, so solve the equation ...
h(x) = 0
-5(x -4)^2 +180 = 0 . . . . substitute for h(x)
(x -4)^2 = 36 . . . . . . . . . . divide by -5, add 36
x -4 = 6 . . . . . . . . . . . . . . positive square root*
x = 10 . . . . . . add 4
The object will hit the ground 10 seconds after launch.
_____
* The negative square root also gives an answer that satisfies the equation, but is not in the practical domain. That answer would be x = -2. The equation is only useful for time at and after the launch time: x ≥ 0.
4y + 3 ≤ y + 6
4y + 3 - 3 ≤ y + 6 - 3
4y ≤ y + 3
4y - y ≤ y - y + 3
3y ≤ 3
3y/3 ≤ 3/3
y ≤ 1
So any value of y less than or equal to 1 (so 1 is included in the solution set) satisfies the inequality. C is the correct answer.
9514 1404 393
Answer:
Step-by-step explanation:
Let x and y represent the weights of the large and small boxes, respectively. The problem statement gives rise to the system of equations ...
x + y = 85 . . . . . combined weight of a large and small box
70x +50y = 5350 . . . . combined weight of 70 large and 50 small boxes
We can subtract 50 times the first equation from the second to find the weight of a large box.
(70x +50y) -50(x +y) = (5350) -50(85)
20x = 1100 . . . . simplify
x = 55 . . . . . . . divide by 20
Using this in the first equation, we can find the weight of a small box.
55 +y = 85
y = 30 . . . . . . . subtract 55
A large box weighs 55 pounds; a small box weighs 30 pounds.
The amount of the first alloy is 450 grams and the amount of the second alloy is 30 grams.
<h3>What is a linear equation?</h3>
It is defined as the relation between two variables, if we plot the graph of the linear equation we will get a straight line.
If in the linear equation, one variable is present, then the equation is known as the linear equation in one variable.
We have:
A chemist has two alloys, one of which is 5% gold and 20% lead and the other which is 30% gold and 50% lead.
Let's suppose the x is the amount of the first alloy and y is the amount of the second alloy:
We can make two linear equation in two variables:
0.05x + 0.3y = 31.5 ...(1)
0.2x + 0.5y = 105 ...(2)
After solving the above two linear equations by substitution method, we get:
x = 450 grams
y = 30 grams
Thus, the amount of the first alloy is 450 grams and the amount of the second alloy is 30 grams.
Learn more about the linear equation here:
brainly.com/question/11897796
#SPJ1
<span>"The company pays $55 a day for food and lodging and $0.45 for each mile traveled" means that if she travels
m miles and is on a trip for
x days then Rita will receive:
55x + 0.45m dollars.
Rita drove 300 miles, means that m=300. Thus </span>
55x + 0.45m becomes <span>
</span>
(dollars.)
She was reimbursed $2,335 means that
.
Part A:
.
Part B:
We are given the equation 55x+135=2,335. Subtracting 135 from both sides we have:
55x=2,335-135=2,200.
Dividing both sides by 55, we get: x=2,200/55=40.
Part C: since x represents the number of days Rita spend on this trip, and x=40, then Rita spent 40 days on this trip.
