Expand and simplify 4(x+5) + 3(x-7)
When we're doing algebra and expanding brackets, our first step is to multiply everything inside each bracket by what we have just before the bracket. Let's start with the 4(x+5). 4 lots of our unknown mystery number x would give us 4x. 4 lots of 5 gives us 20. So together we have 4x + 20. Doing the same for 3(x-7), 3 lots of x gives us 3x. 3 lots of -7 gives us -21. So all together we have 3x-21. Putting both parts together we have 4x + 20 + 3x - 21. Now we need to simplify this. If we write this in a different order with our x's together and our integers (or whole numbers) together we have 4x + 3x + 20 - 21. From here we can see we have 7x - 1. And there's our final answer.
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