Answer:
a) 18
b)x^2+10x+18
c)x^2 -6x+2
Step-by-step explanation:
This is a case of plugging in the value into f(x).
a) f(-8)= -8^2 + 6(-8) +2
f(-8)= 64 + (-48) +2
f(-8)=64 + (-46)
f(-8)=18
b) f(x+2)= (x+2)^2+6(x+2)+2
So here I'll take a break to explain what's going on, because x+2 is a binomial meaning two terms and it is being squared I have to multiply the whole thing by itself. Meaning: (x+2) x (x+2), this is also known as foiling!! and for the next part its distributing 6 into x and 2.
f(x+2)= x^2+4x+4+6x+12+2
I'll reorder it
f(x+2)= x^2+4x+6x+12+2+4
f(x+2)= x^2+10x+18
c) f(-x)= -x^2+6(-x) +2
f(-x)= x^2 -6x+2
Answer:
True
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
Here (h, k) = (- 4, - 9), thus
y = a(x + 4)² - 9
To find a substitute the coordinates of the zero (- 7, 0) into the equation.
0 = a(- 7 + 4)² - 9, that is
0 = 9a - 9 ( add 9 to both sides )
9a = 9 ( divide both sides by 9 )
a = 1, thus
y = (x + 4)² - 9 ← expand factor using FOIL
y = x² + 8x + 16 - 9
y = x² + 8x + 7
A) 8 + 7 + 5 = 20 parts
b) 220 kg ÷ 20 = 11
c) <span> 8 parts crushed gravel: 8 x 11 = 88 kg
7 parts water: 7 x 11 = 77 kg
5 parts cement: 5 x 11 = 55 kg</span>
