Factor the quadratic expression completely.
15x^2-4x-4=

  (3x -2)(5x +2)

Step-by-step explanation:

To factor a quadratic ax²+bx+c, you look for factors of ac that total b. Here, that means you're looking for factors of (15)(-4) = -60 that total -4. We can look at factor pairs of -60 to see what the choices might be:

  -60 = -60·1 = -30·2 = -20·3 = -15·4 = -12·5 = -10·6

The sums of these pairs are -59, -28, -17, -11, -7, and -4. So, the numbers we're looking for are -10 and 6. We can rewrite the expression using these numbers to divide -4x into parts that have the sum of -4x:

  = 15x² -10x +6x -4

Grouping terms in pairs and factoring the pairs gives ...

  = 5x(3x -2) +2(3x -2)

Using the distributive property again, we get ...

  = (5x +2)(3x -2) . . . . . . . . factorization of the given quadratic

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.

3. (5x + 1) - (-10x + 6)

simplify the answer choice. combine like terms. remember to distribute the negative to the terms inside the second parenthesis. also remember that two negatives = one positive, and one of each sign = negative.

- (-10x + 6) = + 10x - 6

simplify. combine like terms:

5x + 1 + 10x - 6

5x + 10x + 1 - 6

15x - 5

∴ it is your answer

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