★ANSWER★
1.)By twice, we mean you add it twice, or ×2.
So we're multiplying by 2, a sum between these two things
A number that we do not know, so we'll call it x
The number 5
So the sum between x & 5 is simply x + 5, and we're multiplying that by 2.
So we're not doing 2x + 5, nor are we doing x + 2×5, because neither of those is "twice the sum" as the question states.
We do 2(x + 5). This tells us that whatever x + 5 turns out to be, we make twice that; and if we were to plug in a number for x, Order of Operations tells us to find the sum before we multiply by two.
2.) x=3
EXPLAINATION:
5(x+6)=45
(I'm using X as the variable to solve for in this equation)
use distribution
5x+30=45
then subtract
45-30=15
then divide yo solve for x
15÷5=3
therefore, x=3.
3.)Let x = the number
Let x = the number2x - 5 = 9
Let x = the number2x - 5 = 92x = 14
Let x = the number2x - 5 = 92x = 14x = 7
thats all i know
#CarryOnLearning
