in the given figure angle D= angle E and triangle abc is isoceles with ac=bc then show that triangle cde similar to triangle??​

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)

approximately 5 hours 32 minutes

let x be the amount of it takes both pumps to fill and 1 pump to empty

so the pumps fill/empty at the rate of per hour

first pump fills at a rate of per hour

second pump fills at a rate of per hour

third pump empties at a rate of per hour

together the reservoir fills at a rate of

+ - =

multiply each term by 720x

120x + 90x - 80x = 720

130x = 720 ( divide both sides by 130 )

x = = 5. hours

(0. × 60 ≈ 32 minutes )

time taken to fill reservoir is 5 hours 32 minutes

x³ - 13x + 12

step-by-step explanation:

if you are familiar with the distributive property

a(b+c) = a·b + a·c

then you can apply this here with the binomials.

since multiplication over the real numbers is commutative, we can multiply these binomials in any order. suppose we want to focus on the product (x - 1)(x + 4)

using the distributive property, we can distribute (x - 1) into (x+4):

(x - 1)(x + 4) = x(x - 1)+ 4(x - 1)

and then we apply the distributive property again:

  = x² - x + 4x - 4

combining like terms -x and 4x, we get that

  = x² + 3x - 4

hence we have that (x - 1)(x + 4) = x² + 3x - 4. in this original product, this means that

  (x - 1)(x + 4)(x - 3) = (x² + 3x - 4)(x - 3)

now we can take (x - 3) to the front

  = (x - 3)(x² + 3x - 4)

and then distribute (x-3) inside

  = x²(x - 3) + 3x(x - 3) - 4(x - 3)

now distribute again

  = x³ - 3x² + 3x² - 9x - 4x + 12

and combine like terms to get a final answer of

  = x³ - 13x + 12