Question

What ten times a number increased by four is no more than twenty-five in numbers

Answer 1

ten times a number. we'll call "a number" x:

`10 * x`
ten times a number increased by four. increased by is a fancy way of saying plus:

`10 * x + 4`
ten times a number increased by four is no more than twenty five. if a number is no more than 25, that means it's either less than 25 or equal to 25. so:

`10 * x + 4 \leq 25\\10x+4 \leq 25`

Answer 2

`10x+4<25 \\\\ 10x<25-4 \\\\ 10x<21 \\\\ x<(21)/(10) \\\\ \boxed{x \in (-\infty; (21)/(10))}`