Answer:
x² +18x +81
Step-by-step explanation:
(a+b)²=a²+b²+2ab
(x+9)² = x²+9²+2*x*9= x² +18x +81
Answer:
Step-by-step explanation:
Easy way to do this is step by step. Your quadratic, from your entry, must be
.
Step by step looks like this, one thing at a time:
becomes
becomes

and this of course is

Do the same with the subtraction sign to get the other solution.
If you're unsure of how to enter it into your calculator, do it step by step so you don't mess up the sign. If you enter it incorrectly, you could end up with an imaginary number when it should be real, or a real one that should be imaginary.
Just my advice as a high school math teacher.
Answer:
12 prob
Step-by-step explanation:
Answer:
7x+12
Step-by-step explanation:
You do 10x-3x since they both have the x variable they can be combined to make 7x and the 12 is left alone.