Translate "difference between twice a number & 4 times the

[willjam179]

Please Help me to solve this algebra problem.

Translate "the difference between twice a number and four times the sum of the number and seven to two" into an equation and solve. The choices are (1) -13 (2) -15 (3) 15 (d) 12

If you can please show me the formula?
Thanks
Brenda

 

[royhaas]

Re: Elementary Algebra Equations

What does "to two" mean? Twice a number is 2n, and 4(n+7) is four times the sum of the number and seven; difference between implies subtraction.

 

[Denis]

Re: Elementary Algebra Equations

Probably forgot "equal" to two;
2n - 4(n + 7) = 2 ; n = -15

 

[BreniChelle.o3]

Probably forgot "equal" to two;
2n - 4(n + 7) = 2 ; n = -15

sir, how it becomes -15 ?
i solved it by this, but i dnt know if its correct

2x-4(x+7) = 2
2x-4(7x) = 2
2x-28x = 2
-26x/-26 (cancel -26) = 2/-26

x= -13 ??

my question is, the x can be add by 7 ? im using PEMDAS ?

 

[srmichael]

sir, how it becomes -15 ?
i solved it by this, but i dnt know if its correct

2x-4(x+7) = 2
2x-4(7x) = 2
2x-28x = 2
-26x/-26 (cancel -26) = 2/-26

x= -13 ??

my question is, the x can be add by 7 ? im using PEMDAS ?

\(\displaystyle x+7 \neq 7x\)

2x - 4(x + 7) = 2
2x - 4x - 28 = 2 (distribution)
-2x - 28 = 2
-2x = 30
x = -15