( substittion method) 2x-3y=12 & x=4y+1 and the other problem is y=-x+5 & x-4y=10 can u plz help me?

Answer 1

2x - 3y=12
x=4y +1

you know what x equals relative to y from the second equation given, so all you have to do is put 4y+1 as the value for x in the first equation. (if you don't know just by looking at it, you can isolate x or y so that you get x= blah or y= blah, and just put into the other equation)

2(4y +1) - 3y = 12

use distributive law and then do algebra to get the value of y

8y + 2 -3y = 12
5y = 10
y = 10/5 = 2

now that you have the value for y, you can put it into any of the two equations to get the value for x. (i picked the second one because it's easier)

x = 4(2) + 1
x=9

For the first problem, x is equal to 9, and y is equal to 2.

put the values into one or both of the equations just to make sure that it's right

2(9) - 3(2) = 12
yay :) got right answer.




y= -x+5
x-4y = 10

you do the same thing as the first problem.

x - 4(-x+5) = 10

use distributive law, then do algebra

x + 4x - 20 = 10
5x = 30
x = 6

put in value of x into an equation to find y.

(6) - 4y = 10
-4y = 4
y = -1

In the second problem, x= 6 and y=-1.

check answers:

(6) - 4(-1)= 10

hope it helped :)

Answer 2

Problem #1:

Eq1. 2x - 3y = 12
Eq2. x = 4y + 1

We know that x is equal to 4y + 1, so we can substitute that in for x in the first Equation:

Eq1. 2x - 3y = 12
2(4y+1) - 3y = 12 Now just solve for y.
8y + 2 - 3y = 12
5y + 2 = 12
5y = 10
y = 2

Now that you know y, you can simply plug your y value into the second Equation to find x.

Eq2. x = 4y + 1
x = 4(2) + 1
x = 8 +1
x = 9

So, the answer to your first problem is: x= 9, y = 2.

Problem #2:

Eq1. y = -x + 5
Eq2. x - 4y = 10

You do this problem in almost the exact same way. The only major difference is that, in this problem, you start with Equation 2 instead of Equation 1. So, I'll just show all of the steps without in-depth explanations.

Eq2. x - 4y = 10
x - 4(-x +5) = 10
x + 4x - 20 = 10
5x - 20 = 10
5x = 30
x = 6

Eq1. y = -x + 5
y = -(6) + 5
y = -6 + 5
y = -1

So, the answer to your second problem is: x = 6, y = -1.


I hope this proves to be helpful. I did my best to show every step, so as not to cause any confusion... but if you have any questions about what I did, feel free to send an e-mail my way and ask! Good luck!

Answer 3

well if x=4y+1, then put 4y+1 in for the x in the 1st problem. so its 2(4y+1)-3y=12. so 8y+2-3y=12. so 5y=10. so y=2. plug that back in the original equation, so 2x-3(2)=12. so 2x-6=12. so 2x=18. so x=9.
do the same for the 2nd set, only plug -x+5 in for y.

Answer 4

1st part
2x-3=12
2(4y+1)-3y=12 substitute x with 4y+1
8y+2-3y=12 distribute
5y+2=12 combine like terms
5y=10 subtract 2 from both sides
y=2 divide by 5
second part
x=4y+1 second equation
x=4(2)+1 (substitute)
x=8+1 simplify
x=9 combine like terms
x=9, y=2

1st part
x-4y=10
x-4(-x+5)=10 substitute the variable
x+4x-20=10 distribute the -1
5x-20=10 combine like terms
5x=30 add 20 to both sides
x=6 divide by 5
2nd part
y=-x+5
y=-6+5 susbstitute the variable
y=-1 combine like terms
x=6 y=-1

Answer 5

Problem one:
E1: 2x-3y=12
E2:x=4y+1

substitute E2 into E1:
2(4y+1)-3y=12
then simplify:
8y+2-3y=12
5y+2=12
5y=10
y=2

then plug 2 in for y in E2 to find x:
x=4(2)=1
x=9

solution to problem 1:
x=9 y=2

Problem 2:
E1: y=-x+5
E2: x-4y=10

substitute E1 into E2:
x-4(-x+5)=10
Simplify:
x+4x-5=10
5x-5=10
5x=15
x=3

then plug 3 in for x in E1:
y=-3+5
y=2

your solution for problem 2 is:
x=3 y=2

Answer 6

17

Answer 7

2x-3y+12 and x-4y+1 then you put that in everytime in the equation you see an "x"

2(4y+1) -3y=12
8y+2-3y=12
-2 -2
8y-3y=10
5y=10
y=2

Answer 8

algebra..............ahhhhhhhhhhhhh........ please don't scare me. don't you get a summer break?
2(4y+1)-3y=12 8y+2-3y=12 5y+2=12 5(2)+2=12 y=2

does that help? I don't understand , does the other one combine with this to figure out the second one's answer?

I hope this helps. Have a great day!

Answer 9

first:
y=2, x = 9

2x-3y=12
x=4y+1
2(4y+1)-3y=12
8y+2-3y=12
5y=10
y=2
2x-6=12
2x=18
x=9

second:
y=-1, x=6

y=-x+5
x-4y=10
x-4(-x+5)=10
x+4x-20=10
5x=30
x=6
y=-6+5
y=-1

Answer 10

the first problem y = 2
the second problem x = 3