The first expression can be simplified by combining like terms.
First, the terms "4b" and "-3b" can be combined to form "b"
Then, the terms "-7" and "9" can be combined to form "2"
Finally, we simply put these two final terms together, to form "b+2"
Hence, 4b-7-3b+9 is equal to be + 2.
Hope this helps!
