First we calculate how many ways you can choose four books from a set of eight.
We use the formula n! / [r! * (n-r)!]
8! / [4! * 4!]
= 8*7*6*5 / 4*3*2*1 = 70 ways
Then we have to calculate how many permutations can be made from 4 objects which equals 4*3*2*1 = 24
So, the TOTAL number of ways = 70 * 24 = 1,680
You need to subtract everything to the left side and set it equal to zero. Combine like terms.
Then, the coefficient of x^2 is a, the coefficient of x is b, and the constant term is c.
4x^2 - 5 = 3x + 4
4x^2 - 3x - 5 - 4 = 0
4x^2 - 3x - 9 = 0
a = 4; b = -3; c = -9
Each side is 4 sq centimeters long.
Answer:
As ΔABC is an <u>isosceles triangle</u>:
⇒ BA = BC
(the dashes on the line segments indicate they are of equal measure)
⇒ ∠BAC = ∠BCA = 55°
⇒ ∠BCA = ∠BAD = 55°
Angles on a <u>straight line</u> sum to 180°
⇒ ∠ADE + ∠EDC = 180°
⇒ 98° + ∠EDC = 180°
⇒ ∠EDC = 82°
As BE intersects AC, the <u>vertically opposite angles</u> are <em>equal</em>:
⇒ ∠BDC = ∠ADE = 98°
⇒ ∠ADB = ∠EDC = 82°
Interior angles in a triangle sum to 180°
⇒ ∠BAD + ∠ADB + ∠ABD = 180°
⇒ 55° + 82° + ∠ABD= 180°
⇒ ∠ABD = 180° - 55° - 82°
⇒ ∠ABD = 43°
Answer:
62 degrees
Step-by-step explanation:
the inside angles of a triangle always equal 180 degrees when added, so i just subtracted 56 and 62 from 180, also, the triangle is isosceles, which has 2 angles of equal value, so the unknown angle had to be equal to 62
