D answer is 9 , 24/8 = 3
3x3=9
f(x) = x³ - 2x² - 24x
x³ - 2x² - 24x = 0
x(x² - 2x - 24) = 0
x = 0
x² - 2x - 24 = 0
a = 1, b = -2, c = -24
Delta = (-2)² - 4 * 1 * (-24) = 4 + 96 = 100
x = (-(-2) - 10)/(2 * 1) = -8/2 = -4
x = (-(-2) + 10)/(2 * 1) = 12/2 = 6
Answer: 2)
13x + 5y = 16
2x - 8y = 20
Multiply the equations;
13x + 5y = 16 [x2]
2x - 8y = 20 [x13]
26x + 20y = 32
26x - 104y = 260
Reverse the signs on one equation;
26x + 20y = 32
-26x + 104y = -260
'-26x' gets cancelled, leaving;
20y = 32
104y = -260
20y + 104y = 124y
32 - 260 = -228
124y = -228
y = -228 / 124
y = -1.84
Substitute in one equation and find 'x'.
Hope this helped! :)
