Answer:
x = 5, -2
Step-by-step explanation:
basic format is ax^2 + bx + c. multiply ac and ask urself what # + what is equal to b? those two same numbers should also multiply to get you ac.
x^2 - 3x - 10 = 0
(x-5) (x+2) = 0
x - 5 = 0 and x + 2 = 0
x = 5 and x = -2
So in this case a= 1 and c = -10. -10 x 1 = -10. -5 x 2 is equal to -10 and -5 + 2 gets you -3, which is b.
I don't think I explained it very well but I hope that helps a little :)
rate of change is the slope
slope = (y2-y1)/(x2-x1)
m= (180-120)/(3-2)
m = 60/1
m = 60
b. point slope form
y-y1 = m(x-x1)
y-120 = 60 (x-2)
c see attached graph. x>=0 since it is hours
d the y intercept is
y -120 = 60x-120
add 120 to each side
y = 60x
Total time = 10/10
So time left = 10/10 - 2/10 - 7/10
= 10/10 - 9/10
= 1/10 (answer)
Answer:
A. 7.5 cm
Step-by-step explanation:
3/4 = (x + 3)/(2x + 1)
3(2x + 1) = 4(x + 3)
6x + 3 = 4x + 12
2x = 9
x = 4.5
BC = x + 3
= 4.5 + 3
= 7.5 cm