Answer:
x = 3 or -7
Step-by-step explanation:
Recall that for a quadratic equation in the form:
Ax² + Bx = C
we need to add (B/2)² to both sides of the equation to
In our case, we are given:
x² + 4x = 21
compared to the general equation above, B = 4, hence we need to add (4/2)² to both sides
x² + 4x = 21 (complete the square)
x² + 4x + (4/2)² = 21 + (4/2)²
x² + 4x + 2² = 21 + 2²
(x+ 2)² = 21 + 4
(x+ 2)² = 25 (take square root of both sides)
(x+2) = ±√25
(x+2) = ±5
hence
(x+2) = +5----> x = 5 - 2 = 3 (answer)
or
(x+2) = -5 ----> x = -5 - 2 = -7(answer)
Answer:
Step-by-step explanation:
3^2 + 1^2 = c^2 (diagonal squared)
9 + 1 = c^2
10 = c*2
is the length
It is irrational because the decimal repeats forever
(30 1/2) / (3 3/4) =
(61/2) / (15/4) =
61/2 * 4/15 =
122/15 =
8 2/15 hot dogs were eaten in 1 minute <==
Answer: 
Step-by-step explanation:

Answer:
the zero of a function is the value of x which makes the final value zero
First Equation:
So let 25 - 2x equal to 0
<em>25 - 2x = 0</em>
x = 12.5
Second Equation:
Let 2x² - 11x - 6 equal to zero
<em>2x² - 11x - 6 = 0 </em>
<em>2x² - 12x + x - 6 = 0 </em><em>(Splitting the middle term)</em>
<em>2x(x - 6) + 1(x - 6) = 0</em>
<em>(2x + 1) (x - 6) = 0</em>
So we can transpose either one of the brackets below the zero
(2x + 1) = 0 or (x-6) = 0
x = -1/2 or x = 6