Answer:
x = - 2.5
Step-by-step explanation:
Given that the sketch represents
y = x² + bx + c
The graph crosses the y- axis at (0 , - 14), thus c = - 14
y = x² + bx - 14
Given the graph crosses the x- axis at (2, 0), then
0 = 2² + 2b - 14
0 = 4 + 2b - 14 = 2b - 10 ( add 10 to both sides )
10 = 2b ( divide both sides by 2 )
b = 5
y = x² + 5x - 14 ← represents the graph
let y = 0 , then
x² + 5x - 14 = 0 ← in standard form
(x + 7)(x - 2) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 7 = 0 ⇒ x = - 7
x - 2 = 0 ⇒ x = 2
The x- intercepts are x = - 7 and x = 2
The vertex lies on the axis of symmetry which is midway between the x- intercepts, thus
the x- coordinate of the turning point is 
= 
= - 2.5
Questions:
(a) What is a simplified expression for (x + y) – (x – y)?
(b) Carlotta thinks that 
is the same as 
. Which statement shows that it is NOT the same?
Answer:
Step-by-step explanation:
Solving (a):
Given
Required
Simplify
Open brackets
Collect Like Terms
Solving (b):
Given
and
Required
Which expression shows they are not the same
The expression that shows this is:
Take for instance; y=2
Substitute 2 for y in
Evaluate all exponents
The above expression supports
9514 1404 393
Answer:
the correct choices are shown
Step-by-step explanation:
<u>Statement</u> . . . . . <u>Reason</u>
1. c ║ d; ∠4 = ∠5 . . . . . Given
2. ∠4 = ∠7 . . . . . Alternate interior angles are equal
3. ∠5 = ∠8 . . . . . Vertical angles are equal
4. ∠7 = ∠8 . . . . . Substitution
