You can write this as two equations, then solve them.
let B be the board length, let T be the total length
so we have...
4B = T+3
3B = T-5
we need to make both equations equal to T, so we can later remove that variable:
T+3 - 3 = 4B - 3
Therefore: T = 4B-3
T-5 + 5 = 3B + 5
Therefore : T = 3B+5
Because they are both equal to T we can make them equal to eachother and reorder the equation to get B on one side:
4B - 3 = 3B + 5
4B - 3 + 3 - 3B = 3B + 5 + 3 - 3B
therefore B = 8
thus we know that the board's length is 8ft long,
Hope this helps! :)
25-13=12 dollars to spend on MP3 downloads
12/0.75=16.
16 downloads.
Answer:
-4 and -16
Step-by-step explanation:
Let x = first number
Let y = second number
Given:
- The two numbers multiply to 64
⇒ xy = 64
Given:
- The two numbers add to -20
⇒ x + y = -20
Rewrite x + y = -20 to make x the subject:
⇒ x = -20 - y
Substitute into xy = 64 and solve for y:
⇒ (-20 - y)y = 64
⇒ -20y - y² = 64
⇒ y² + 20y + 64 = 0
⇒ (y + 4)(y + 16) = 0
⇒ y = -4, y = -16
As x + y = -20
If y = -4 then x = -16
If y = -16 then x = -4
Therefore, the two numbers are -4 and -16
