Answer:
X= 1 AND 13
Step-by-step explanation:
x2+14x = -13
by completing the square method
you add the square of half the coefficient of b to both sides
which is (14/2)^2
x^2+14x+(7^2) = -13 +(7^2)
x^2 + 7^2 = -13 + 49
x^2 + 7^2 = 36
(x + 7)^2 = 36
find the square root of both sides
(x+7) = + or - 6
x=7-6 ; 1
or
x= 7+6 ; 13
so, the 2.5oz cake will be "x" calories, pheeew, she'll be taking in 900 - x less calories.
13c+17c=14+22
30c=36
c=36÷30
c=6÷5
So c= 6 over 5
5/9 is closer to 1
Hope this helps!
Answer:
b) i) Curve A
ii) - 1.75
iii) x = 1 - √5 or x = 1 + √5
Step-by-step explanation:
b) i) We are given a function y = x² - 2x - 3 and the graph of this function is also shown in the side diagram.
The equation can be rearranged to y = (x - 1)² - 4
⇒ (x - 1)² = y + 4
Therefore, this is an equation of a parabola having the vertex at (1,-4) point and its axis is parallel to the positive y-axis.
So, the curve A represents the equation given. (Answer)
ii) Now, at x = 2.5, f(x) = 2.5² - 2 × 2.5 - 3 = - 1.75 (Answer)
iii) When y = 1, then x² -2x - 3 = 1
⇒ x² - 2x - 4 = 0
⇒ (x - 1)² - 5 = 0
⇒ (x - 1)² - (√5)² = 0
⇒ (x - 1 + √5)(x - 1 - √5) = 0
⇒ x = 1 - √5 or x = 1 + √5 (Answer)
