Answer:
x = - 7, x = 3
Step-by-step explanation:
To find the x- intercepts let f(x) = 0 , that is
x² + 4x - 21 = 0
Consider the factors of - 21 which sum to give the coefficient of the x- term (+ 4)
The factors are + 7 and - 3, since
7 × - 3 = - 21 and 7 - 3 = + 4, then
x² + 4x - 21 = 0
(x + 7)(x - 3) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 7 = 0 ⇒ x = - 7
x - 3 = 0 ⇒ x = 3
Answer:
13meters
Step-by-step explanation:
c^2=a^2+b^2
12^2+5^2=169
find squareroot of 169 which is 13meters
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
