when a number is added to 4, the result is equal to subtracting 10 from three times of it. what is the number? For these types of problems you need to translate the sentence into a mathematical statement. First, let x = the number. The question asks when a number, x, is added to 4 the result is equal...we'll stop there for now. Right away we can write when a number is added to 4 as x+4. The result is equal to subtracting 10 from three times that number or 3x-10. In other words, x+4 = 3x-10. Now, we simply solve for x. Let's simplify by subtracting x from both sides. 4 = 2x-10 Now add 10 to both sides to isolate the x term 14 = 2x Divide each side by 2 x = 7. Now let's check to see if that's correct. We do this by substituting 7 into the original equation wherever x occurs. 7+4 = 3(7)-10 11 = 11. It checks out. Therefore x = 7 is the correct answer.