Anyone Know System of Equations

1)
-2x+5y= -3
+ 2x+3y=11 (I rearranged the equation so the x's and y's lined up-ALWAYS do that!...-2x-3y=- 11 is the same as 2x+3y=11)
8y=8
y=1 Answer is C

2) again-ALWAYS rearrange the equations so the x's and y's line up!
(-4x+2y= -2)-3
+ 12x-3y= 4

gives you....
12x -6y=6
+ 12x -3y=4

and then you can just multiply ONE of those by -1 to get rid of the x's and solve for y. Answer is D.

3)
0.35(120)+40=Company A 14(5)+ 0.30(120)=Company B
42+40=A 70+36=B
A=$82 B=$106

Answer is B.

4) Rearrange equations so x's and y's line up.
3x+8y=7
+ -3x+4y=2
12y=9 Answer is B.
y=12/9=4/3 or 1 1/3

5)
4.35
- 4.00 (1 sandwich + 2 colas=4.35, so to find value of 1 cola subtract 4.00 which = 1 cola +
0.35 1 sandwich)
so each cola costs $0.35....SO....
4.00
- .35
3.65 each sandwich costs $3.65. Answer is A.

Better to put one question per .......
-2x + 5y = -3
-11 + 2x = -3y
Get them in the same form
-2x + 5y +3 = 0
2x + 3y - 11 = 0
------------------------------- add the two equations
0 + 8y + (-8) =0
8Y = 8 so Y = 1 so C
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12x - 3y = 4
-2 - 2y = -4x to standard form......
12x-3y+4 = 0 A
4x -2Y -2 = 0 B
crappy question, I would go with ? ... but solve the problem
Multiply B by 3 and then subtract the two equations to eliminate the X variable
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3. Moving van company A charges a $40.00 fee to rent a van. In addition to this fee, they charge $0.35 a mile. Moving van company B charges $14.00 a day and $0.30 a mile to rent their vans. Aaron needs to rent a moving van for 5 days. He will be driving 120 miles. Which company should Aaron choose if he wants to spend the least amount of money?
PA= 40+(0.35*120)
PB=(14*5) + .3*120
Co A is cheaper
Gotta run
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