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Seven more than the product of a number and three is equal to four

1 Answer

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First, write this out as an equation

"Seven more" means 7 plus something. "the product of a number and three" Product means multiply and the "a number", we don't know that number. So use a variable (we'll use x) to represent it. "is equal to four" pretty straight forward. = 4. Okay, let's write this out:

7 + x3 = 4

3 is written right next to x (with no space) to indicate multiplication. Now we need to solve this. Let's get x by itself on the left side of the equal sign. Start by subtracting 7 from BOTH sides.

7-7 = 0 (we dont write the zero) and 4 - 7 = -3.

So now we have;

x3 = -3

x still isn't by itself. 3 is still stuck to it, so let's undo that. Since 3 is being multiplied by x, DIVIDE it.

x3 divided by 3 = x. -3 divided by 3 = -1.

So, x = -1.

To make sure this is true, substitute -1 in for x.

7 + (-1)3 = 4

(USE ORDER OF OPERATIONS!)

7 + -3 = 4 (-1 * 3 = -3)

4 = 4 (7 + -3 is the same as 7 - 3, which is 4. 4 = 4 , so this is correct!)

User Charlie Guo
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