I am having some math problems. Can someone please solve these questions with step-by-step answers:
Question: Use the substitution to solve each system of equations. If the system does not have exactly one solution, state whether it has no solution or infinitely many solutions.
3x-y= 4
2x-3y= -9
2.5x+y= -2
3x+2y= 0
x+4y= 8
2x-5y= 29
2x+2y= 7
x-27= -1
Thank you.
2007-02-10 21:00:23 · 5 answers · asked by IAnswerQ 4 in Science & Mathematics ➔ Mathematics
3x-y= 4
2x-3y= -9
y=3x-4
2x-3(3x-4)=-9
2x-9x+12=-9
-7x=-21
x=3
sub
y=3*3-4
=5
2.5x+y= -2
3x+2y= 0
-10x-2y=4
3x+2y=0
adding
-7x=4
x=-4/7
substituting
-12/7+2y=0
y=6/7
x+4y= 8
2x-5y= 29
-2x-8y=-16
2x-5y=29
adding
-13y=13
y=-1
substituting
x-4=8
x=12
2x+2y= 7
x-27= -1
x=28
56+2y=7
2y=-49
y=-49/2
2x-49=7
2x=56
x=28
2007-02-10 21:08:18 · answer #1 · answered by raj 7 · 2⤊ 1⤋
counting on which variable you're keeping apart you may take 2 strategies to this. mindset a million : sparkling up equation A for x. A) x = a million-y substitute (a million-y) into equation B) anyplace you notice an x. B) 5(a million-y)-4y =-7 5 - 5y - 4y = -7 5 - 9y = -7 -9y = -12 y = 4/3 use this answer to sparkling up x in equation A) A) x = a million-y x = a million-(4/3) x = 3/3 - (4/3) = -a million/3 mindset 2 follows a similar path yet via simplifying equation A for y instead of x.
2016-11-03 03:25:38 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Question 1
-9x + 3y = -12
2x - 3y = - 9
-7x = -21
x = 3
9 - y = 4
y = 5
Question 2
-5x - 2y = - 2
3x + 2y = 0
-2x = -2
x = 1
3 + 2y = 0
2y = -3
y = -3/2
Question 3
-2x - 8y = -16
2x - 5y = 29
-13y = 13
y = -1
2x + 5 = 29
x = 12
Question4
According to how it is typed, x = 26
52 + 2y = 7
2y = -45
y = -45/2
However, I am going to assume equations are:-
2x + 2y = 7
x - 2y = -1
3x = 6
x = 2
4 + 2y = 7
2y = 3
y = 3/2
Please select suitable answer for question 4
2007-02-10 23:16:36 · answer #3 · answered by Como 7 · 0⤊ 1⤋
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3x-y= 4
2x-3y= -9
y=3x-4
2x-3(2x-4)=-9
2x-6x+12=-9
-4x=-21
x=21/4
sub
y=63/4-16/4
=47/4
2.5x+y= -2
3x+2y= 0
-10x-2y=4
3x+2y=0
adding
7x=4
x=4/7
substituting
12/7+2y=0
y=-6/7
x+4y= 8
2x-5y= 29
-2x-8y=-16
2x-5y=29
adding
-13y=13
y=-1
substituting
x-4=8
x=12
2x+2y= 7
x-27= -1
x=28
56+2y=7
2y=-49
y=-49/2
2x-49=7
2x=56
x=28
2007-02-10 22:13:13 · answer #4 · answered by Anonymous · 0⤊ 1⤋
dude do ur own hw or ask ur teacher for help the next day if u don't get it..if ppl do it for u will be stupid.
2007-02-10 21:06:58 · answer #5 · answered by Apollos 1 · 0⤊ 0⤋