Answer:
Step-by-step explanation:
1) 2x -y = 1 -------1
3x - y = -6 ------2
Subtract eqn 2 from eqn 1
-x = 1--6 = 7
x = -7
Put x= -7 in eqn 1
2*-7-y = 1
-14-y = 1
- y = 15
y = -15
2) 4x +2y = 10------1
y = 4x + 2--------2
Put eqn 2 in eqn 1
4x + 2 ( 4x+ 2) = 10
4x + 8x + 4 = 10
12x = 6
x = 6/12 = 1/2
Put x = 1/2 in eqn 2
y = 4* 1/2 + 2= 2 + 2
= 4
3) 6x - y = 2------1
y = 3x + 4---------2
Put eqn 2 in eqn 1
6x - (3x +4) = 2
6x - 3x - 4 = 2
3x = 6
x = 2
y = 3*2 + 4 = 6 + 4
= 10
Answer:
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
Step-by-step explanation:
Confidence interval:
Sample mean plus/minus the margin of error.
In this question:
Mean of 23.
Margin of error 2.1.
Then
23 - 2.1 = 20.9
23 + 2.1 = 25.1
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
Answer:
D. 4 x -2 - 7/8
Step-by-step explanation:
4 x -2 7/8
2 7/8 can be separated into 2 pieces 2 +7/8
4x - (2+7/8)
Distribute the minus sign
4x - 2 -7/8
Answer:
x +3 = x^2 +2x -4
Step-by-step explanation:
Straight substitution of the top expression for y gives you ...
x +3 = x^2 +2x -4
__
This lets you rewrite the equation to standard form as ...
x^2 +x -7 = 0
and find the solutions to be ...
x = (-1±√29)/2
Corresponding y-values will be 3 more than this:
y = (5±√29)/2
