Answer:
30
Step-by-step explanation:
x + 23 = ?
x = 7
All we need to do is plug in x =7 to the first equation:
7 + 23 = ?
We simplify and get:
30 = ?
X= weight of TV
y= weight of CD
3x+5y= 62.5
3x+ 2y= 52
You can either solve for a variable, or eliminate a variable by subtracting the second equation from the first:
3x + 5y = 62.5
-(3x+2y = 52)
0 + 3y = 10.5, so y = 10.5/3 or 3.5.
Now plug y= 3.5 back into any equation to get x:
3x + 5(3.5) = 62.5
3x + 17.5 = 62.5
3x = 45
x = 15
Always check work. Both equations should be true for x=15, y= 3.5
Answer: 3x-5y=-9 is simplified to y=3/5x+9/5
x+2y=8 is simplified to y=-1/2x+4
An addition sign between 978 and 842 would make the equation true!
