Algebra help once again??

Question

Find four solutions for the equation 3x + 5y = 15.

Thank you.

Answer 1

3x + 5y = 15
This is an equation of 2 unknowns (x,y)
In your question, you're asking for 4 solutions. There is an infinite number of solutions. All you have to do is pick an unknown and ssign it a number. Then solve a single unknown equation (linear equation).

for example let y = 6
3x + 5(6) = 15
3x + 30 = 15
3x = -15
x = -15/3
x = -5
therefore (-5,6) is a solution

now try x let x = 20
3(20) + 5y = 15
60 + 5y = 15
5y = 15-60
y = -45
y = -9

therefore (20, -9) is another solution.

Answer 2

To find multiple solutions for a two variable equation like this one, you can solve for either of the variables (most students, teachers, and textbooks say solve for y). Then replace x with values and find the value of y.

To work this problem, first solve for y.
5y = 15 - 3x (subtract 3x from both sides)
y = 3 - (3/5)x

Now, replace x with values to get the y value.
(NOTE: if you don't want fractions, like most of my students, use a multiple of 5, so the fraction will disappear when multiplying x by 3/5)

Let x = 0, ... y = 3 - (3/5)0 = 3
Let x = 5, ... y = 3 - (3/5)5 = 3 - 3 = 0
Let x = 10,... y = 3 - (3/5)10 = 3 - 6 = -3
Let x = -5,... y = 3 - (3/5)(-5) = 3 + 3 = 6

So, four solutions are (0, 3) , (5, 0) , (10, -3), and (-5, 6)

Answer 3

x= 5 and y=0 or
x=0 and y=3

Answer 4

3x +5y =15

first solve equation for x or y, I chose to do x

3x= 15-5y
x= (15/3) - (5y/3)
x = 5 - (5y/3)

OK now chose whatever you want for y value... 0, 1, -3, 8000, whatever... and solve for x like so


x=5 -(5y/3) try y =0
x= 5 -(5*0/3)
x=5 -0
x=5

so y= 0, x=5

now try y=3

x= 5 - ((5*3)/3)
x=5 - (15/3)
x=5 - 5
x=0

so y=3, x=0

get the idea??... I bet you can do a third one on your own...

Answer 5

put x=0, 3*0+5y=15
5y=15
y=15/5
y=3
put x=1, 3*1+5y=15
3+5y=15
5y=15-3
5y=12
y=12/5
put x=2, 3*2+5y=15
6+5y=15
5y=15-6
y=9/5
put x= -1, 3*-1+5y=15
-3+5y=15
5y=15+3
5y=18
y=18/5
so four solutions are (0,3), (1,12/5), (2,9/5), (-1,18/5)

Answer 6

you need to solve for x and y by doing a similtaneous equation.

3x=15-5y
then divide the whole equation by 3 to find out x.let x equal 0 and then u will be able to calculate y.

Answer 7

3x+5y=15
or, y = (15-3x)/5
SOLUTIONS ARE:
x = 0, y = 3
x= 5, y = 0
x=10, y=-3
x=4, y=3/5=0.6
x=2, y=9/5=1.8

Answer 8

x = 0, y= 3
x=5, y=0
x= -5, y = 6
x= 10, y= -3

Answer 9

X=5
Y=0

X=0
Y=3

SORRY, I CAN ONLY FIND 2 ANSWERS. HOPE THIS HELPS.

Answer 10

isolate each veriable