Let 11x + 15y + 23 = 0 be equation (1)
And 7x - 2y - 20 = 0 be equation (2)
Multiply equation (1) by 2:
22x + 30y + 46 = 0
Multiply equation (2) by 15:
105x - 30y - 300 = 0
Add equations (1) and (2):
22x + 105x + 30y - 30y + 46 - 300 = 0
127x - 254 = 0
127x = 254
x = 254/127
[x = 2]
Substitute x = 2 in equation (1) to find y:
11(2) + 15y + 23 = 0
22 + 15y + 23 = 0
15y + 45 = 0
15y = -45
y = -45/15
y = -3
Therefore, x = 2 and y = -3.
Answer:
a = -3
Step-by-step explanation:
Solve for a:
2 (a + 5) - 1 = 3
Hint: | Distribute 2 over a + 5.
2 (a + 5) = 2 a + 10:
(2 a + 10) - 1 = 3
Hint: | Group like terms in 2 a - 1 + 10.
Grouping like terms, 2 a - 1 + 10 = 2 a + (10 - 1):
(2 a + (10 - 1)) = 3
Hint: | Evaluate 10 - 1.
10 - 1 = 9:
2 a + 9 = 3
Hint: | Isolate terms with a to the left hand side.
Subtract 9 from both sides:
2 a + (9 - 9) = 3 - 9
Hint: | Look for the difference of two identical terms.
9 - 9 = 0:
2 a = 3 - 9
Hint: | Evaluate 3 - 9.
3 - 9 = -6:
2 a = -6
Hint: | Divide both sides by a constant to simplify the equation.
Divide both sides of 2 a = -6 by 2:
(2 a)/2 = (-6)/2
Hint: | Any nonzero number divided by itself is one.
2/2 = 1:
a = (-6)/2
Hint: | Reduce (-6)/2 to lowest terms. Start by finding the GCD of -6 and 2.
The gcd of -6 and 2 is 2, so (-6)/2 = (2 (-3))/(2×1) = 2/2×-3 = -3:
Answer: a = -3
The expression that represents the ratio of the difference of the two means to Sidney’s mean absolute deviation is given by: Option B: 4/3.28
<h3>What is mean absolute deviation?</h3>
Mean absolute deviation is the average of the absolute deviation of each observation from their mean, for a considered set of observations.
For this case, the table of mean and mean absolute deviation is given as:
(M.A.D refers to Mean Absolute Deviation).
So, difference in their mean is 82 - 78 = 4
Absolute deviation for Sidney is 3.28
Thier ratio is: 4/3.28
Thus, the expression that represents the ratio of the difference of the two means to Sidney’s mean absolute deviation is given by: Option B: 4/3.28
Learn more about ratio here:
brainly.com/question/12106245
We know that 1 gram = 10 decigrams
That means that 650 * 10= 6500
Hope this helps!
