X - the number
3(x+1)=2x+4
3x+3=2x+4
3x-2x=4-3
x=1
After the donation,
3m + m = 132
manual = 33
digital = 99
Before the donation, he had 82 more digital and 26 more manual cameras.
82 + 99 = 181 digital
26 + 33 = 59 manual
For a double check, before donation,
digital + manual = 240
181 + 59 = 240
So, to begin with, the number of digital cameras = 181.
2x - 3y = -24
x+ 6y = 18
you solve the first one by the x:
2x = -24 + 3y
x = (-24+3y)/2
then you substitute what you found in the other equation and you solve by y
(-24+3y)/2 + 6y = 18 multiply everything by 2
-24 + 3y + 12y = 36
3y + 12y = 36 + 24
15y = 60
y = 60/15
y = 4
Good job! You found your y! :D
Now let's substitute the y in the first equation with 4:
2x - 3(4) = -24
2x - 12 = -24
2x = -24 + 12
2x = -12
x = -12/2
x= -6
Done!! ;) <span />
