Factor x3 – 4x2 + 7x – 28 by grouping. what is the resulting expression? (x2 – 4)(x + 7) (x2 + 4)(x – 7) (x2 – 7)(x + 4) wrong answer (x2 + 7)(x – 4)

(x² + 7)(x – 4)

Step-by-step explanation:

To factor by grouping, we group together the first two terms and the last two terms in parentheses:

(x³ - 4x²) + (7x - 28)

Factor out the GCF of each group.  For the first group, the largest factor is x²:

x²(x-4) + (7x-28)

The GCF of the second group is 7:

x²(x-4) + 7(x-4)

The GCF of the two groups is now x-4:

(x-4)(x²+7)

30 feet

step-by-step explanation:

that would be 2 1/2 * 12

= 24 + 6

= 30 feet   (answer)

answer: the angel abc is 30°,and the abc is a triangle where the angel bac is 90°

so ac is the half of 24=12ft,and from the pythagorean theorem we find ba

ba=√bc^2-ac^2=√576-144=√432=12√3ft

so bac is 12+12√3=12(1+√3)ft