$3$ times a number, plus $4$, is equal to $10$ I was helping my brother with his math homework and there was this question:
$3$ times a number, plus $4$, is equal to $10$. What is that number?
My first thought was that $3x+4 = 10$ and then, solve for $x$. But then, my brother told me maybe it’s $3(x+4)=10$. Now I’m confused too. Which one is right? I think it’s the former given that “plus $4$” was in-between commas but I’m not sure.
Thanks in advance!

Almost certainly the problem is intended to be $3x+4=10$.
But your brother has made an important discovery. Until the sixteenth century, all mathematical textbooks would write out such problems in words, like "3 times a number, plus 4, is equal to 10". As your and your brother have discovered, this can be difficult to interpret correctly, and certainly takes up a lot of space. If simply writing down a mathematical equation is difficult and time consuming and error prone then it makes you less likely to spend time working out how to solve the equation. And if you do find a method of solving a particular type of equation then it is much harder to explain your method to other people.
The adoption of standard mathematical symbols such as $+$ and $=$ and the use of letters like $x$ to stand for unknown quantities was a big step forwards in the development of modern mathematics.
