Which of the following are solutions to the quadratic equation below? Check all that apply.
x2 + 8x - 9 = 0
A. 1
B. 3
C. -3
D. -9
E. -1

Step-by-step explanation:

Given quadratic equation is:

x² + 8x - 9 = 0

Using mid-term break formula

x² + 9x - x - 9 = 0 (When we multiply middle terms, we get side terms as answer which is mid term break formula.)

Taking common

x(x + 9) - 1(x + 9) = 0

Take (x + 9) common

(x + 9)(x - 1) = 0

According to zero's method:

Either:

x + 9 = 0      OR    x - 1 = 0

x = -9           OR       x = 1

Hope this helped!

b. 2

step-by-step explanation:

the slope of a line =δy/δx

δy= y₂-y₁

δx= x₂-x₁

therefore, using the points (-2,-3)   and (3,7) we can calculate gradient as follows:

m=(7--3)/(3--2) (a number minus a negative number the sign changes to a plus)

m=(7+10)/(3+2)

=10/5

=2

  or  

sin y = 7/q

7 is the opposite side length, q is the hypotenuse

tan y = 7/r

7 is the opposite side length, r is the adjacent side length

using sohcahtoa ^^^^

cos y = adjacent/hypotenuse

cos y = r/q