Math(please check)

posted by .

Simplify each expression:

1) (x+8)^2 = x^2 + 64

2) (x-2)^3 = x^3 - 8

3) (x-2y)(x+y) = x^2 - xy -2y^2

4) (x+2)(x^2+3x-2) = x^3 + 5x^2 + 4x-4

Are my answers correct?

  • Math(please check) -

    Numbers 3) and 4) are correct.

    For numbers 1) and 2), you have missed out terms, probably you have not used the right standard formulae.

    (a+b)² = a² + 2ab + b²
    (a-b)² = a² - 2ab + b²
    (a+b)³ = a³ + 3a²b + 3ab² + b³
    (a-b)³ = a³ - 3a²b + 3ab² - b³

    If you are in an examination where you do not have an easy way to double check the standard formulae, you can treat
    (a+b)² = (a+b)(a+b)
    which you seem to have no problem solving.

  • Math(please check) -

    so for (x+8)^2 i would use
    a^2 + 2ab + b^2 and a would be 8 but what is b? Would it be 64?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Algebra 1: 8th Grade

    Simplify each expression. Write your answers using positive exponents. Check Answers Please: 1) 2^3*2^4 = 2^7 2)10^6/10^9 = 1/10^3 3)3^5*3^1 = 3^6 4)5^7*5^-4 = 5^3 5)9^3/9^-10 = 9^13 6) 4^11/4^8*4^-2 = 4^5 7) a^2*a^3 = a^5 8)b^-9/b^4 …
  2. Math

    Please check my work. 1) 64 divide -4 = -16 2) -144 divide (-9) = 16 3) Simplify -9 and a small 2 = -81 4) Simplify (-3) and a small 3 = -27 5) Add -4/11 + 5/11 = 1/11 6) subtract 5/11- [-3/11] = 8/11 7) multiply [-7/8] • [-2/4] …
  3. Algebra (check my answers)

    Please check these answers. Multiply -7(2a2 -4) = -14a2 + 28 Multiply 0.5(a + b -5) = 0.5a + 0.5b - 2.5 Factor bx - by + bz = b(x - y + z) Combine like terms (simplify) 12x + 4 - 11y - 6x - 9 - y = 6x - 12y - 5 Evaluate the expression …
  4. Algebra

    Can you please check my work? You have helped other students I know. Thank you:) Multiply -7(2a2 -4) = -14a2 + 28 Multiply 0.5(a + b -5) = 0.5a + 0.5b - 2.5 Factor bx - by + bz = b(x - y + z) Combine like terms (simplify) 12x + 4 -
  5. algebra 2

    1.Simplify the difference. n^2 - lOn+24 9 / n^2 - 13n + 42 — 7 A. n-13/n-7 <<< B. n-4/n-7 C. n-13 2.Simplify the complex fraction. y-1/y^2+y-6/y-6/y+3 A.(y-1)(y-6)/(y+3)^2(y-2) B. y-1/(y-6)(y-2) C.(y-1)(y-6)/(y+3)(y-2)<<< …
  6. Math check my answers

    Please check my answers on the following questions Simplify: (X^6)^1/2 = x^3 1000000^1/6 I don't know this one (64n^12)^-1/6 = 1/0.5n^2 (9n^4)^1/2. = 3n^2 36^3/2 = my answer is 2 in the index of the aware root of 36^3 343^-4/3 I don't …
  7. Algebra 1--Please, check my answers!

    Multiply. Simplify your answer. 1. (n + 3/n- 5) x (n^2 - 5n) A: n^2 + 3n 2. (6xy^2/2x^2y^6) x (6x^4y^4/9x^3) A: 2 3. (3h^3 - 6h/10g^2) x (4g/g^2 - 2g) (This is the correct expression. There is no typo.) A: ?
  8. Math Please Check

    Please check my answers! Thank you! Simplify the following expressions. Collapse “x” terms, and/or simplify fractions and exponents. 1.) (12/5) / (36/20) = 4/3 2.) x^13*x^3 = x^16 3.) x^4 / (x^2)^3 = 1/x^2 4.) x^-3 / x^2 = x^-5 …
  9. Algebra

    1. Simplify the expression: 4√18+5√32 A.45√2 B.32√2 C.116√2 D.9√50 2. Simplify the expression: 7√5-3√80 A.-5√5 B.-4√75 C.-5 D.4√-75 3. Simplify the expression: √21(√3+√14) …
  10. Algebra

    1.Simplify the radical expression. √5+6√√5 A.5√5 B.7√10 C.7√5 D.5√10 2.Simplify the radical expression. 2√6+3√96 A.14√6 B.14√96 C.5√96 D.50√6 3.Simplify …

More Similar Questions