Solve the system by substitution.
x + y = 5
y = x – 1

Question

Solve the system by substitution. 
                x + y = 5
		y = x – 1

solomonzelman · Answer

Look at what y equals to in the second equation. See it? Substitute that instead of y into the first equation.

solomonzelman · Answer

x + y = 5
y = x – 1

x + (x-1) = 5
x=?    SOLVE FOR X....

anonymous · Answer

i got three is that right

solomonzelman · Answer

Yes x=3!


Can you solve for y?

solomonzelman · Answer

But, not you, @kimmybowlin  I want @Ambbiiee  to do it, since she is the one that asked.

anonymous · Answer

ok

anonymous · Answer

this is algebra right

solomonzelman · Answer

Yes, this is algebra 1.

anonymous · Answer

y-5=-2y+1 
y+2y=1+5 
3y=6 
y=6/3 
y=2

anonymous · Answer

ok i passed it a while ago and was trying to see if i still have my skills that were portrayed during that time. but thank you!!:)

solomonzelman · Answer

Yes, that's correct y=2...

@Ambbiiee  if you will, can you right the answer as an (x,y) coordinate? You absolutely don't have to do it, I just want to see you do it:)

solomonzelman · Answer

I am not sure what exactly are you doing here -:(

anonymous · Answer

how did you guys get 3

anonymous · Answer

x+(x-1)=5
2x-1=5
   +1  +1
2x=6
/2   /2
x=3

solomonzelman · Answer

x + y = 5
y = x – 1

substitution

x+(x-1)=5
x+x-1=5
2x-1=5   (add 1 to both sides)...
2x=6
x=3


x + y = 5
3 + y = 5  (subtract 3 from both sides)
y = 2

solomonzelman · Answer

Makes sense @Ambbiiee , right?

anonymous · Answer

slowly coming to an understanding @SolomonZelman

solomonzelman · Answer

alright, I can explain it a little better, or give you more time....