Question

if the sum of a number and seven is doubled, the result is two less than the number. find the number.

Answer 1

2(x + 7) = x - 2
2x + 14 = x - 2
2x - x = -2 - 14
x = -16

check..
2(-16 + 7) = -16 - 2
2(- 9) = - 18
-18 = -18 (correct)

x = -16

Answer 2

Do you think you can change the words into the "math" ?

sum of a number and seven

when you see a vague term like "a number", give it a name (people like to use "x" )
sum of x and 7
now write that as x+7

to continue
the sum of a number and seven is doubled
(x+7) is doubled
doubled means we have twice as much. if we had x we would have 2x
in this case, we have (x+7), so now we have 2(x+7)

Answer 3

the result is two less than the number

"the result is" turns into =
(often the "IS" is a clue to put in an equal sign)

2(x+7) = two less than the number
change two to 2 and "the number" to x
2(x+7) = 2 less than x

you should learn that 2 less than x means x-2
2 more than x would be x+2

so we now have
2(x+7) = x-2
now it is algebra.

Answer 4

-16

Answer 5

Yes, kellie showed the algebra up above.