MATH HALP PLEEESE I NEEED IT

(2x + 3)(x - 7)

Step-by-step explanation:

Given

2x² - 11x - 21

Consider the factors of the product of the x² term and the constant term which sum to give the coefficient of the x- term

product = 2 × - 21 = - 42 and sum = - 11

The factors are - 14 and + 3

Use these factors to split the x- term

2x² - 14x + 3x - 21 ( factor the first/second and third/fourth terms )

= 2x(x - 7) + 3(x - 7) ← factor out (x - 7) from each term

= (2x + 3)(x - 7) ← in factored form

10.416 m/s

step-by-step explantion:

distance=100m

time= 9.6s

average speed=100/9.6

=10.416 m/s

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!