Solve the system of equations given below.
5x + 4y = 25
3x + 4y = 15
(5, 0)
(0, 0)
(0, -5)
(-5, -5)
2007-04-28 16:56:11 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
You could just check the solutions to see which one works, but to solve it... you could do linear combinations.
5x + 4y = 25
3x + 4y = 15
If you subtract the two equations you get...
2x = 10
x = 5
Substitute 5 for x in either of the equations to find y
5(5) + 4y = 25
25 + 4y = 25
4y = 0
y = 0
The solution is (5, 0)
2007-04-28 17:00:41 · answer #1 · answered by suesysgoddess 6 · 1⤊ 0⤋
Answer = A. 5x + 4y = 25
- (3x + 4y = 15)
2x = 10
x = 5
plug 5 back into a equation to find y, turns out to be zero
2007-04-28 17:01:28 · answer #2 · answered by smartguy41090 2 · 0⤊ 0⤋
Just try each answer in the equation and you'll see the first answer is correct.
If x equaled 5 and y equaled 0 then it would be as follows:
(5 x 5) + (4 x 0) = 25
(3 x 5) + (4 x 0) = 15
2007-04-28 17:03:35 · answer #3 · answered by thelensgirl 2 · 0⤊ 0⤋
(5,0)
Because the y-coefficients are the same, we will subtract the equations.
5x + 4y = 25
3x + 4y = 15
------------------
2x =10 ===> divide by 2
x = 5 , now plug in and solve for y
5x + 4y = 25
(5)(5) + 4y = 25
25+ 4y = 25 ===> subtract 25 each side
4 y = 0 ===> divide by 4
y = 0
=)
(5,0)
2007-04-28 17:00:35 · answer #4 · answered by Anonymous · 0⤊ 0⤋
it has to be (5,0)
Plug each value in... the first # in each ordered pair is the x and the second number in each ordered pair is y.
5(5)+4(0)=25....... it turns out to be 25+0=25 which is good.
3(5)+4(0)=15....... it turns out to be 15+0=15 which is good.
It cant be the negatives becuz then your answer would be in negatives... and it cant be (0,0) becuz then it would be 0+0 which is 0... and none of them equal 0.
2007-04-28 17:10:41 · answer #5 · answered by YankeeZ_FaN 4 · 0⤊ 0⤋
I wish I was the first to answer...
So, let's check by trial and error here.
(5,0) === (5*5)+(4*0)=25
(5,0) === (5*3)+(4*0)=15
CORRECT!
So, fast forwarding through the other ones...
(0,0) = 0
WRONG!
(0, -5) = -20 (both equations)
WRONG!
(-5, -5) = -40
b) -35
WRONG!
So...
x=5, y=0.
2007-04-28 17:07:54 · answer #6 · answered by Anonymous · 0⤊ 0⤋
5x+4y-25=0
3x+4y-15=0
__________ subtract the equation
2x-10=0
2x=10
x=5
5(5)+4y-25=0
4y=0
y=0
(5,0)
2007-04-28 17:10:28 · answer #7 · answered by nicole 2 · 0⤊ 0⤋
by pluggin in the values..only the 1st one works
2007-04-28 16:58:37 · answer #8 · answered by bid 1 · 0⤊ 0⤋
5,0
2007-04-28 18:08:25 · answer #9 · answered by Kristenite’s Back! 7 · 0⤊ 0⤋