Why is x2 (x5) not x10. Why is it x7?

When adding or subtracting common terms (same variable), the exponents stay the same.

Example:

(3x2+ 2) + (4x2- 5)

= 3x2+ 2 + 4x2- 5 {took out parentheses}

= 7x2- 3 {combined like terms, exponents do not change}

When multiplying common terms (same variable), you add the exponents.

Example:

2x3(4x2)

= 8x5{when multiplying, add the exponents}

Additional note:

-When you are dividing common terms (same variable), you subtract the exponents.

Example:

x8/x3= x5{when dividing, subtract the exponents}

- Algebra House

Example:

(3x2+ 2) + (4x2- 5)

= 3x2+ 2 + 4x2- 5 {took out parentheses}

= 7x2- 3 {combined like terms, exponents do not change}

When multiplying common terms (same variable), you add the exponents.

Example:

2x3(4x2)

= 8x5{when multiplying, add the exponents}

Additional note:

-When you are dividing common terms (same variable), you subtract the exponents.

Example:

x8/x3= x5{when dividing, subtract the exponents}

- Algebra House