7 / 1/3
therefore
21 x 1/3= 7
Answer:
The number is 7
Step-by-step explanation:
certain positive number: x
x is multipled by 4:
4x
result of this is subtracted from the original number:
so original number minus 4x,
x - 4x
the result is 21 less than 0, this means negative 21
x - 4x = 0 - 21 = -21
do algebra:
-3x = -21
multiply both sides by -1
3x = 21
divide both sides by 3
x=7
(certain positive number: x) is equal to 7
Answer: it is 3 • (x + 4)
Step-by-step explanation: We move all terms to the left:
4-2x+8-(+5x)=0
We add all the numbers together, and all the variables
-2x-(+5x)+12=0
We get rid of parentheses
-2x-5x+12=0
We add all the numbers together, and all the variables
-7x+12=0
We move all terms containing x to the left, all other terms to the right
-7x=-12
x=-12/-7
x=1+5/7We move all terms to the left:
4-2x+8-(+5x)=0
We add all the numbers together, and all the variables
-2x-(+5x)+12=0
We get rid of parentheses
-2x-5x+12=0
We add all the numbers together, and all the variables
-7x+12=0
We move all terms containing x to the left, all other terms to the right
-7x=-12
x=-12/-7
x=1+5/7