11) -x + y = -1 ; 2x - y = 0
y = -1 + x ; 2x - (-1+x) = 0 ⇒ 2x + 1 - x = 0 ⇒x = -1
y = -1 + (-1) ⇒ y = -2
12) -2x + y = -20 ; 2x + y = 48
y = -20 + 2x ; 2x + (-20 + 2x) = 48 ⇒ 2x -20 + 2x = 48 ⇒ 4x = 48 + 20
4x = 68 ⇒ x = 68/4 ⇒ x = 17
y = -20 + 2(17) ⇒ y = -20 + 34 ⇒ y = 14
13) 3x -y = -2 ; -2x + y = 3
y = 3 + 2x ; 3x - (3 + 2x) = -2 ⇒ 3x - 3 - 2x = -2 ⇒ x = -2 + 3 ⇒ x = 1
y = 3 + 2(1) ⇒ y = 3 + 2 ⇒ y = 5
14) x - y = 4 ; x - 2y = 10
x = 4 + y ; (4 + y) - 2y = 10 ⇒ 4 + y - 2y = 10 ⇒ 4 - y = 10
⇒ -y = 10 - 4 ⇒ -y = 6 ⇒ y = -6
x = 4 + (-6) ⇒ x = 4 - 6 ⇒ x = -2
15) x + 2y = 5 ; 3x + 2y = 17
x = 5 - 2y ; 3(5-2y) + 2y = 17 ⇒ 15 - 6y + 2y = 17 ⇒ -4y = 17 - 15
⇒ -4y = 2 ⇒ y = -2/4 ⇒ y = -1/2
x = 5 - 2(-1/2) ⇒ x = 5 + 2/2 ⇒ x = 5 + 1 ⇒ x = 6
Answer:
The answer to your question is 0 < x ≤ 3/14
Step-by-step explanation:
Here are the steps to solve it.
First, you need to solve your inequality step-by-step:
3/x −2 ≥ 12
-2x + 3/x = ≥12
Next, find the critical points of the inequality:
2x + 3/x = 12
−2x + 3 = 12x (Multiply both sides by x)
−2x + 3 − 12x = 12x − 12x (Subtract 12x from both sides)
−14x + 3 = 0
−14x + 3 − 3 = 0 − 3 (Subtract 3 from both sides)
−14x = −3
-14x/ -14 = -3/ -14 (Divide both sides by -14)
So, that gives you your answer:
x = 3/14
Answer:
Step-by-step explanation:
The solution is in the attached file
Answer:
y = 6 or 8
Step-by-step explanation:
1. Subtract the constant:
y^2 -14y = -48
2. Add the square of half the y-coefficient:
y^2 -14y +49 = -48 +49
Write as a square, if you like:
(y -7)^2 = 1
3. Take the square root:
y -7 = ±√1 = ±1
4. Add the opposite of the constant on the left:
y = 7 ±1 = 6 or 8
The solution is y = 6 or y = 8.
The sample which is likely to produce the most valid result is Richard's sample because there was no statistical bias. Statistical bias is the systematic favoritism of certain individuals in the study. Just like what Adriana, Henry and Malik did in conducting their surveys, they choose people who are point of interest and also who are near them. In the way Richard conducted his survey, he used a random sampling technique, this is a method of selecting a sample from a population in such a way that every possible individual can be chosen and he doesn't know who these people are.