How do you solve this quadratic equation

5x(squared)+16x-84=0

preferably if you could show me step by step using the quadratic equation. with answers please! thank you

formula: -b+√(b^2-4ac)
2a

a = 5, b = 16, c = -84

plug in: -16+√(16^2-4(5)(-84))
2(5)

simplify: -16+√(256+1680)
10

solve: -16+√(1936)
10

lastly: 1. solve that by adding the √(1936) , then dividing by 10
2. solve that by subtracting the √(1936) , then dividing by 10

You will end up with 2 answers.

Alright, Anyacito, in your problem you have: 5x^2 + 16x - 84 = 0. The Quadratic Formula is:
x = -b +/- sqrt[(b^2 - 4ac)/2a]. Just use the coefficients: a = 5, b = 16 and c = -84, and plug them in: x = -16 +/- sqrt[(16^2 - (4 x 5 x -84)/( 2 x 5)]
x = -16 +/- sqrt[ 265 - ( -1680/ 10)]
= -16 +/-sqrt[ 265 - ( -168)]
= -16 +/-sqrt 433
= -16 +/- 20.8087 (Round off to 21)
= -16 + 21 and -16 - 21
x = 5 and -37 There are two possible answers to this problem as the positive (+) and negative (-) sign before the square root sign. Just follow this example for other problems, you will be just fine!

5x^2 + 16x - 84 = 0
=> 5x^2 + 30x - 14x - 84 = 0
=> 5x (x+6) - 14 (x+6) = 0
=> (5x-14) (x+6) = 0