Question

OPTIONS:

Answer 1

You have to combine like terms (terms that have the same variable(x,y....) and power/exponent)²³

(4x³ - 4 + 7x) - (2x³ - x - 8)        Distribute -1 into (2x³ - x - 8)

(4x³ - 4 + 7x) + (-)2x³ - (-)x - (-)8   (two negative signs cancel each other out and become positive)

(4x³ - 4 + 7x) - 2x³ + x + 8    Now combine like terms

4x³ - 2x³ + 7x + x - 4 + 8     (I rearranged for the like terms to be next to each other)

2x³ + 8x + 4       It is equivalent to B

$(-3x^2+x^4+x)+(2x^4-7+4x)$       Combine like terms

$-3x^2+x^4+2x^4+x+4x-7$    (I rearranged for the like terms to be next to each other)

$-3x^2+3x^4+5x-7$    It is equivalent to D

(x² - 2x)(2x + 3)      Distribute x² into (2x + 3) and distribute -2x into (2x + 3)

(x²)2x + (x²)3 + (-2x)2x + (-2x)3

When you multiply a variable with an exponent by a variable with an exponent, you add the exponents together

2x³ + 3x² - 4x² - 6x      Combine like terms

2x³ - x² - 6x         It is equivalent to A

[Info]

When you multiply a variable with an exponent by a variable with an exponent, you add the exponents together. (You can combine the exponents only if they have the same variable)

For example:

$x^{2} (x^3)=x^{(2+3)}=x^5$

$(y^3)x^2=y^3x^2$         (You can't combine them because they have different exponents of y and x)

$(5^2)(5^4)=5^{(2+4)}=5^6=15,625$