Answer:
Let's see what we know first, we know that sum means addition, and number would be a variable, let's say x. the problem is asking to find the number in this case its the x. Now that we know what we have here let's put it into an equation like so:
48+2x=58 <--- we translated what the words mean into equation form
Now we subtract 48 from both sides:
2x=10
Finally we divide both sides by 2 to see what the value of x is:
x=5
let's check now to make sure that the answer 5 is correct by plugging it back into the equation as so:
48+2x=58 <--- original equation
48+2(5)=58 <--- substitute x for 5 from our answer earlier
48+10=58 <--- add 48 and 10
58=58
We have 48+2x=58 or 2x=10 or x=5.