im suuppeerr confused with this can someone help me understand how to do this (for medal and maybe fan)

Question

anonymous · Answer

A pair of equations is shown below:

y = 6x + 9
y = 7x + 7 

What is the solution to the pair of equations?

 (–2, 21)
 (2, 21)
 (–2, –21)
 (2, –21)

anonymous · Answer

b

anonymous · Answer

is correct answer

mehek14 · Answer

first, substitute the first equation into the second one

anonymous · Answer

want explination

anonymous · Answer

how do i solve lol yea ok @Mehek14  then what

mehek14 · Answer

$6x + 9= 7x + 7 $
then, combine like terms
$7x-6x=x\9-7=2\x=2$

mehek14 · Answer

so you have $(2,?)$
we need to find the y value
so plug 2 in 6x + 9
$6*2+9\6*2=12\12+9=21\(2,21)$

anonymous · Answer

ohhh ok thanks lol id fan you but i already did but if i have another question like this can you work it out with me you explained it good i just have different kind of that concept hard to explain lol

mehek14 · Answer

ok