Answer:
A quick way to calculate upper and lower bands is to halve the degree of accuracy specified, then add this to the rounded value for the upper bound and subtract it from the rounded value for the lower bound.
Answer:
the answer is 12
Step-by-step explanation:
7x-2y-1. x=3. y=4
7×3-2×4-1
=21-8-1
=12
1. 4x + 8y = 12....divide by 4
x + 2y = 3
2y = -x + 3
y = -1/2x + 3/2...slope is -1/2, y int is 3/2
x + 2y = -3
2y = -x - 3
y = -1/2x - 3/2...slope is -1/2 and y int is -3/2
when the slopes are the same, and the y int are different, then the lines are parallel and never intersect...so they have no solution and are inconsistent
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2. y = 2x - 1...slope is 2 and y int is -1
y = -2x + 5 ...slope is -2 and y int is 5
when the slopes are different and the y int are different, then there is 1 solution making it independent
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3. 4x - 12y = 8...divide by 4
x - 3y = 2
same as other equation meaning the equations are the same line...meaning they have infinite solutions making them dependent
-3 • (5x + 2y = 7)
-15x - 6y = -21
-2x + 6y = 9
__________
-17x = -12
x = 12/17
5(12/17) + 2y = 7
2y = 7 - 60/17
2y = 3.47
y = 1.735