Solve equation by using the quadratic formula. 2x²-5x-7​

3.5 or -1 first of all know the formula method , I Don't have the right symbols so I don't want to confuse you so the number infront of x^2 or any alphabet with a square is a , b is the number infront of the letter without a square and c is the single number without an alphabet, this is the easiest formula compared to factorization method so check online or your textbook for the formula

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!