Question

3x+(5/2)y=21
x+2y=14
can someone help me solve this plzzz.

Answer 1

You can find x in terms of y by rearranging the second equation as follows:
x + 2y = 14
Therefore:
x = 14 - 2y
Do you understand this first step?

Answer 2

your subtracting 2y from both sides?

Answer 3

Yes, you are correct. Now we can plug this expression for x into the first equation
3x + (5/2)y = 21
giving
3(14 - 2y) + (5/2)y = 21
which expands to
42 - 6y + (5/2)y = 21
Can you now solve this last equation to find the value of y?

Answer 4

first I think is 21 - 42 which is -2. 6y + (5/2)y= -21 after that i'm kinda confused

Answer 5

\[3x+ \frac{5}{2}y=21\]
\[x+2y=14\]

I think dealing with the fraction is a chore... maybe we can multiply 2 throughout the first equation so we can have whole numbers to work with

Answer 6

yea im not good with fractions

Answer 7

\[3(2)x+ \frac{5(2)}{2}y=21(2)\]
\[6x+ 5y=42\]
\[x+2y=14\]

Answer 8

we could use subsitution by using the second equation
x=14-2y
and then plug it into the first equation

Answer 9

\[6(14-2y)+ 5y=42\]

Answer 10

The equation simplifies to
- (7/2)y = -21
Now you can multiply both sides by -2 to give
7y = 42

Answer 11

6

Answer 12

yes y = 6 is correct.

Answer 13

\[84-12y+5y=42 \rightarrow 84-7y=42\]
\[-7y=42-84 \rightarrow -7y=-42 \rightarrow y=6\]

Answer 14

yup y = 6

Answer 15

yay :D

Answer 16

so now we can plug y = 6 back into
one of the equations.. let's try the second equation

x+2y = 14

Answer 17

x+2(6)=14
x+12=14

Answer 18

Which shows there is more than one way to skin a cat, if you forgive the analogy :)

Answer 19

ewwww I own cats in real life

Answer 20

x=2 n I had a cat once

Answer 21

My bad form :(

Answer 22

yes so x = 2 and y = 6
we can plug it back into the original equations to see if we have the right answer.. I know we do because
2+2(6)=14
2+12=14
14=14

Answer 23

thank u

Answer 24

3(2) +5/2(6/1) = 21
6+(30/2)=21
6+15=21
21=21