SOLUTION: I'm trying to solve by elimination but the answers just don't seem right?
#1) 5x-7y=-16 10x-14y=32 5x-7(-7.90)=-16
2x-5y=11 10x+25y=-55 5x+55.3=-16
Algebra.Com
Question 218322: I'm trying to solve by elimination but the answers just don't seem right?
#1) 5x-7y=-16 10x-14y=32 5x-7(-7.90)=-16
2x-5y=11 10x+25y=-55 5x+55.3=-16
11y=-87 -55.3 -55.3 (-14.26,-7.90)
y=-7.90 5/5x = -71.3/5
x = -14.26
#2) 5x-9=7 7y-3x=-5
+9 +9 7y-3(16/5)=-5
5/5x=16/5 7y-42=-5 (16/5, 37/7)
x = 16/5 +42 +42
7/7y = 37/7
y = 37/7
#3) 9x+5y=6 2(3/11)-5y=-3
2x-5y=-3 6/11-5y=-3
11/11x = 3/11 -6/11 -6/11
x = 3/11 -5/-5y=-27/-5
y = -27/-5
#4) 8x-3y=16 (8/16,-4)
8x+3y=-8
Thanks.
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
5x-7y=-16 Eqn 1
10x-14y=-32 Eqn 1 times 2
2x-5y=11 Eqn 2
10x-25y=55 Eqn 2 times 5
10x-14y=-32 Eqn 1 times 2
------------------------- Subtract
-11y = 87
y = -87/11
-------------
2x + 435/11 = 11 Eqn 2
2x = -314/11
x = -157/11
------------
------------
11y=-87 -55.3 -55.3 (-14.26,-7.90)
y=-7.90 5/5x = -71.3/5
x = -14.26
--------------
#2) 5x-9=7 7y-3x=-5
+9 +9 7y-3(16/5)=-5
5/5x=16/5 7y-42=-5 (16/5, 37/7)
x = 16/5 +42 +42 **************** 3*16 = 48, not 42
7/7y = 37/7
y = 37/7
#3) 9x+5y=6 2(3/11)-5y=-3
2x-5y=-3 6/11-5y=-3
11/11x = 3/11 -6/11 -6/11
x = 3/11 -5/-5y=-27/-5 ******* -3 - 6/11 = -39/11
y = -27/-5 ****************** y = 39/55
-------------
#4) 8x-3y=16 (8/16,-4) --> (1/2,-4)
8x+3y=-8
RELATED QUESTIONS
Solve by elimination:
1.8x + 11y= 20
5x - 11y= -59
2. 2x + 18y= -9
4x + 18y= -27
(answered by jim_thompson5910)
I'm trying to solve a few equations that I just can not seem to understand, please... (answered by solver91311)
Good morning, can you please help be with the step by step to solving the following... (answered by ikleyn,Alan3354)
Use substitution or elimination to solve each system of equations. Please explain.... (answered by jim_thompson5910)
Ok so I've tried to do this problem quite a few times and I just can't seem to get it.... (answered by stanbon,solver91311)
I am trying to help my 9th grade brother with his homework. He does not have his text... (answered by checkley71)
solve by the elimination method
2x-4y=20... (answered by richwmiller)
Solve the system using the substitution method. Show all your steps.
1. x+2y=6... (answered by checkley79)
What is the solution to the system of equations:
2x +5y + 2z = 6
5x - 7y = -29
z = 1
(answered by Annabelle1,Earlsdon)