There's a special case of the quadratic formula called the Shakespeare Quadratic Formula (2b or -2b) that applies when the linear coefficient is even.

If you're planning on solving a lot of quadratic equations quickly, it's good to know.
Here we have

so


There is 14 beads, and out of it there are 4 red ones. You will divide 4 by 14, and get 0.28. 0.28 is equal to 28%
Answer:
1) 29
2) 64
you can use the explanation below to help find the other 6 problems
Step-by-step explanation:
1) 4(5+6) - 15 = 4 * 11 - 15 = 44 - 15 = 29
2) 8(2+4) + 16 = 8 * 6 + 16 = 48 + 16 = 64
Answer: 2.11cm
Step-by-step explanation:
Given the following :
The lengths of the parallel sides are (2z + 3) cm and (6z – 1) cm
The area of trapezoid is calculated using the formula:
1/2(a + b) × h
Where ;
a = Length of side 1
b = length of side 2
h = height
Take a = (2z + 3) and b = (6z – 1), h = z
Therefore ;
1/2 (2z + 3 + 6z - 1) × z
Opening the bracket
(z + 1.5 + 3z - 0.5) × z
(4z + 1 ) × z = 20cm^2
4z^2 + z = 20cm^2
Using Quadratic formula:
4z^2 + z - 20 = 0
a = 4, b = 1, c = - 20
(-b±√b^2 -4ac) / 2a
Z = 2.11 or - 2.364
z cannot be negative, therefore,
Z = 2.11 cm