Answer:
11x
Explanation:
How do you simplify and combine like terms?
Like Terms: Terms that have identical variable parts (same variable(s) and same exponent(s)). When simplifying using addition and subtraction, you combine “like terms” by keeping the "like term" and adding or subtracting the numerical coefficients.
Simplify 3x + 4x
Looking at these two terms, I see that each contains the variable x, and the variable has the same (understood) power of 1 in each term. So these are like terms, and I can combine them.
Back in grade-school arithmetic, "three apples plus four apples" got combined into "seven apples" by adding the three and the four to get seven, and bringing the "apples" along for the ride. In the same way, I will combine these two like terms by adding the numerical portion of each term, while carrying the x along for the ride:
3x + 4x
(3 + 4) x
(7) x
I showed every step above in order to highlight how the terms are being combined. I'm adding the 3 and the 4, and carrying the x along with the numerical result. My answer is:
7x
Simplify 2x2 + 3x – 4 – x2 + x + 9
It is often best to group like terms together first, and then simplify:
2x2 + 3x – 4 – x2 + x + 9
(2x2 – x2) + (3x + x) + (–4 + 9)
(2 – 1) x2 + (3 + 1) x + (5)
(1) x2 + (4) x + 5
x2 + 4x + 5