Is the coordinate (1, 2) a solution of the system below?
x + 2y = 5
y = x + 1

a. yes

b. no

Test them
(x,y)
x=1 and y=2

x+2y=5
1+2(2)=5
1+4=5
5=5
true

y=x+1
2=1+1
2=2
true

yes
my answer is A

Hello there!

x + 2y = 5
y = x + 1

We gonna solve y = x + 1 for y
Let's start solving the equation by substitute x + 1 for y in x + 2y = 5
x + 2y = 5 (we gonna replace y by x +1)
x + 2( x + 1) = 5
x + 2x + 2 = 5
3x + 2 = 5
3x = 5 - 2
3x = 3
x = 3/3
x = 1

Since we have the value for x, it will be easier for us to find y. In order to find y we just need to replace x by its value which is 1. So let's go!

We have y = x + 1 >> so we gonna substitute 1 for x
y = x + 1
y= 1+1
y=2
see easy :)

The final answer is: (1,2)
The correct option is A (Yes)