Answer:
2/5
Step-by-step explanation:
please mark brainliest
Answer: 9 inches.
Do the pythagorean theorem to find your answer.
Formula: a^2 + b^2 = c2
12 = b
15 = c
a^2 + 12^2 = 15^2
Simplify the equation
a^2 + 144 = 225
Subtract 144 on both sides.
a^2 = 81
Square root of 81 is 9.
You are buying 2 items so let's use two different variables to represent each:
p = number of tubes of paint
b = number of disposable brushes
cost = price per item × number of items
Equations from information given:
4p + 0.50b = 20 ← from the first 2 sentences
2p = b ← if there are twice as many brushes as paint tubes you need 2 times paint tubes to equal number of brushes
Solve the problem by using substitution... 1b equals 2p so replace b with that:
4p + 0.50(2p) = 20
4p + 1p = 20 ← 0.50 is half so half of 2p is 1p
5p = 20 ← combine like terms
p = 4 ← divide both sides of the equation by 5
Recall the equation 2p = b replace p with 4
2(4) = b
8 = b
ANSWER:
You purchased 4 tubes of paint and 8 disposable brushes.
<h3>
Answer:</h3>
D. This is an experiment because it is applying a treatment
<h3>
Step-by-step explanation:</h3>
Experiments and observational studies are both ways to find new information about a hypothesis but in different ways.
Vocabulary
First, to understand the question, let's define the key terms.
- Experiment - An experiment is when a scientist purposely applies a treatment and interferes with a person's life in order to gather information.
- Observational Study - This type of study attempts to study a person without interfering with their lives in any way.
These definitions eliminate the answer choices A and C because both of them match the incorrect definition of the term.
Experiment vs. Observational Study
Now, we need to figure out if this specific example is an experiment or an observational study. In this case, the nutritionist is giving a treatment of vitamins. This means that this cannot be an observational study because the scientist is interfering with people. It has to be an experiment because there is a specific treatment being applied.
First you need to get two similar terms to eliminate, I'll do y:
-3x + 2y = 10
-4x - 2y= -10
And then you minus
x = 20
Now you can substitute x in to one of the equations to find y:
-60 + 2y = 10
+ 60
2y = 70
÷ 2
y = 35
So your values are y = 35 and x = 20. Hope this helps!
