Answer:
x = 0
y = -2
Step-by-step explanation:
The given system of equation are:
5x + y = -2
2x - 2y = 4
The problem here is to find x and y from the expression
5x + y = -2 ----- i
2x - 2y = 4 ---- ii
So;
i x 2 : 10x + 2y = -4 ---- iii
ii x 5 : 10x - 10y = 20 ----- iv
iii - iv; 12y = -24
y = -2
Now find x;
5x + y = -2
5x - 2 = -2
x = 0
Answer:
The radius of the scoop is r = 3.1 cm
Step-by-step explanation:
Since 3 gallons yields 90 scoops, and 1 gallon = 3785 cm³.
3 gallons = 3 × 3785 cm³ = 11355 cm³
So we have 11355 cm³ in 3 gallons which is also the volume of 90 scoops.
Since 90 scoops = 11355 cm³, then
1 scoop = 11355 cm³/90 = 126.2 cm³
Now, if each scoop is a sphere, the volume is given by V = 4πr³/3 where r is the radius of the scoop. Since we need to find the radius of the scoop, r, making r subject of the formula, we have
r = ∛(3V/4π)
Substituting V = 126.2 cm³, we have
r = ∛(3× 126.2 cm³/4π)
= ∛(378.6 cm³/12.57)
= ∛30.13 cm³
= 3.1 cm
So, the radius of the scoop is r = 3.1 cm
Answer:
32.17
Step-by-step explanation:
× ![r^{2}](https://tex.z-dn.net/?f=r%5E%7B2%7D)
A=
×
≈ ![32.16991](https://tex.z-dn.net/?f=32.16991)
A= ![32.17](https://tex.z-dn.net/?f=32.17)
To solve these problems, we must remember the distributive property. This property states that a coefficient being multiplied by a polynomial in parentheses is equal to the sum of the coefficient times each of the separate terms. Using this knowledge, let's begin with number 21:
-(4x + 17) + 3(7-x)
To begin, we should distribute the negative sign through the first set of parentheses and the coefficient of positive 3 through the second set of parentheses.
-4x - 17 + 21 - 3x
Next, we must combine like terms, or add/subtract the constants terms and the variable terms in order to create a more concise expression.
-7x + 4 (your answer)
Now, we can move on to question 22 and solve it in a similar manner:
7(2n-8) - 4(12 - 8n)
Again, we will distribute the coefficients through the parentheses. However, keep in mind that the coefficient in front of the second set of parentheses is actually a NEGATIVE 4, so we must distribute the negative as well.
14n - 56 - 48 + 32n
Next, we will combine like terms (add the n terms together and subtract the constant terms).
46n - 104
Now, we can solve problem 23:
8 + 2(5f - 3)
We will again distribute through the parentheses:
8 + 10f - 6
Combine like terms after that:
10f + 2
Therefore, your answers for the three problems are as follows:
21) -7x + 4
22) 46n - 104
23) 10f + 2
Hope this helps!