33: 21 ...........................................
Answer:
C. 88
Explanation:
f(x) = 4x + 8 || g(x) = x² + x
fg( -5 )
go from right to left in such function problems.
replace x with [ -5 ]
f( (-5)² -5)
f(20)
[ replace x with 20 ]
4(20) + 8
80 + 8
88
X² + 3x = 10
Convert to standard form.
x² + 3x - 10 = 0
factor x² = x * x
factor -10 = 5 * -2
(x + 5) (x - 2) = 0
x(x -2) + 5(x-2) = 0
x² - 2x + 5x - 10 = 0
x² + 3x - 10 = 0
x + 5 = 0 x² + 3x = 10
x = -5 -5² + 3(-5) = 10
25 - 15 = 10
10 = 10
x - 2 = 0 x² + 3x = 10
x = 2 2² + 3(2) = 10
4 + 6 = 10
10 = 10
the answer is B)
we can check by multiply them
2x² + 3x -8 = 0
a = 2 , b = 3 , c = -8
So..
D = b²-4ac = 9 + 64 = 73
for bigger solution , use x = -b + √D / 2a
For smaller solution, use x = -b - √D / 2a
So
= -3 + √73 / 2. 2
= 1/4 (√73 -3)
Hopefully helpfull.. ^_^
