Answer:
D
Step-by-step explanation:
Given the 2 equations
4x - 5y = 18 → (1)
3x - 2y = 10 → (2)
Multiplying (1) by 3 and (2) by - 4, then adding will eliminate the x- term
12x - 15y = 54 → (3)
- 12x + 8y = - 40 → (4)
Add (3) and (4) term by term to eliminate x, that is
- 7y = 14 ( divide both sides by - 7 )
y = - 2
Substitute y = - 2 into either of the 2 equations and solve for x
Substituting into (1)
4x - 5(- 2) = 18
4x + 10 = 18 ( subtract 10 from both sides )
4x = 8 ( divide both sides by 4 )
x = 2
solution is (2, - 2 ) → D
Answer:
(8,-3)
Step-by-step explanation:
(x1+x2/2), (y1+y2/2)
7+9/2=16/2=8 x=8
-5-1/2=-6/2=-3 y=-3
4/7m = 2/7(2m + 1)
4/7m = 4/7m + 2/7
4/7m - 4/7m = 2/7
0 = 2/7 (incorrect)
no solution
Answer:
Find the LCD of the first two, then the LCD of that and the third one.
Step-by-step explanation:
You can do it by finding the LCD of two of the denominators, then the LCD of that and the third denominator.
Or, you can factor each of the denominators and find their LCM by multiplying the unique factors to their highest powers.
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<u>Example:</u>
1/21 + 1/35 + 1/45
The LCD of 1/21 and 1/35 is (21·35)/5 = 105. The LCD of 1/105 and 1/45 is ...
(105·45)/15 = 315
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Using factoring ...
- 21 = 3·7
- 35 = 5·7
- 45 = 3²·5
LCD = 3²·5·7 = 315
