Question

Solve the following system.
y = x + 4
5x + y = 16

(2, −6)

(−2, 6)

(6, 2)

(2, 6)

Answer 1

You could substitute y with x + 4 in the second equation right there.

\( \color{Black}{\Rightarrow 5x + x + 4 = 16}\)

Solve for x, and then add 4 to get the value of y.

Answer 2

All you need to do it plug in the equation for y anywhere you see y in the second equation. Once you do that, you can solve for x in that equation. Using the value of y you found, plug it back into the first equation and solve for y.

Answer 3

*err I meant "value of x you found" in that last sentence...but you get the idea.

Answer 4

See I did what yall are saying but I got 1.5 for y and idk how that happened.

Answer 5

Well, using ParthKohli's equation above, x = 2. You got that far right?

Answer 6

I did it the way I was though and I took the first equation and made it into y = mx + b to which gave me x = y + 4 then i sub it into the 2nd equation and got 1.5 /:

Answer 7

You took the wrong off ramp :) This isn't a slope problem...it's a system of equations.

Answer 8

y=mx+b doesn't have anything to do with this.

Answer 9

yes b/c the first equation has to be put like that to be substituted, this is the way the teacher taught me

Answer 10

Well, you could solve it using the first equation. See where y is 4 more than x, and that'd simply be the answer!

Answer 11

I got the answer its( 2, 6 ) i plugged it into my graph cal.

Answer 12

Yep

Answer 13

Well it's the only answer where you see that y is 4 more than x :)

Answer 14

I would do back-substitution which is what we showed you...that's easier in my mind and is less confusing.

Answer 15

I don't see the point of trying to put it in slope-intercept form....but that's just me :)

Answer 16

Yea totally understandable. Idk why she make us do all this when there is easier ways.

Answer 17

On a test like an SAT you could of course just skip all that and see that y = x +4 basically tells you which answer makes sense

Answer 18

putting y = x + 4 in 5x + y = 16
6x=16-4
x=2
putting x=2 in y = x + 4
y=6
hope u lyk dis

Answer 19

(2,6) is right answer. please give me medal if you like my answer!

Answer 20

To simplify it in simple way,

Write first equation is standard form i.e, x + y = c

So, you will get,

x - y = -4 ---------------1

And the second equation given is:

5x + y = 16 ---------------2

Just add the two equations,

x + 5x = -4 + 16

6x = 12
Here solve for x and then put the value of y in any of the above given equation you will have your answer...