College algebra help needed.?

Question

multiply:

(5√(6)-15√(7)) ((4√(6)+12√(7))=




use rational expressions to write (x^1/3)( y^1/6)(z^1/9) as a single rational expression.



simplify by factoring.
√(80a^2b)


rewrite the following expression with positive exponents.
(5xy)^-8/9

Answer 1

simplify by factoring.
√(80a^2b) = 80a^b

rewrite the following expression with positive exponents.
(5xy)^-8/9 = (5xy)^9/8

Answer 2

(5√(6)-15√(7)) (4√(6)+12√(7))
120 + 60 √(42) - 60√(42) - 180 x 7
700 + 560 + 120
1380

(x^1/3)( y^1/6)(z^1/9); least common denominator: 18
(x^6/18)(y^3/18)(z^2/18)
therefore,
=18throot(x^6 y^3 z^2)

√(80a^2b)
=√(2 x 2 x 2 x 2 x 5 x a^b x a^b)
= 2 x 2 x a^b √5
= 4a^b √5

(5xy)^-8/9
= 9throot[1/(5xy)^8]
= 9throot[(1/5xy)^8]
= (1/5xy)^8/9 or 1/(5xy)^8/9

yey!

Answer 3

(5√6 - 15√7) (4√6 + 12√7)

= 5*4*6 + 5*12*√(6*7) - 15*4*√(6*7) - 15*12*7

= 120 + 60√42 - 60√42 - 1260 = -1140
______________

[x^(1/3)] [y^(1/6)] [(z^(1/9)] = (x^6 y³z²)^(1/18)
__________

√(80a²b) = √(16*5a²b) = 4a√(5b)
___________

(5xy)^(-8/9) = 1/(5xy)^(8/9)

Answer 4

hi just easily multiply the terms together and u will see after simplification that only (5*4*6)-(15*12*7) will remain and just calculate it.