Answer:
(y - 2)²
Step-by-step explanation:
9y² - 12y + 4 ← is a perfect square of the form
(ax - b)² = a²x² - 2abx + b²
Compare like terms with 9y² - 12y + 4, thus
a² = 9 ⇒ a = 3
b² = 4 ⇒ b = 2 and
- 2ab = - 2 × 3 × 2 = - 12
Thus
9y² - 12y + 4 = (3y - 2)²
Recall that A = 1/2bh.
We are given that h = 4+2b
So, putting it all together:
168 = 1/2 b(4+2b)
168 = 1/2(4b + 2b^2)
168 = 2b + b^2
b^2 + 2b - 168 = 0.
Something that multiplies to -168 and adds to 2? There's a trick to this.
Notice 13^2 = 169. So, it's more than likely in the middle of the two numbers we're trying to find. So let's try 12 and 14. Yep. 12 x 14 = 168. So this factors into (b+14)(b-12) So b = -14 or b =12. Is it possible to have a negative length on a base? No. So 12 must be our answer.
Let's check this. If 12 is our base, then according to our problem, 2*12 + 4 would be our height... or 28. so what is 12 * 28 /2?
196. Check.
Hope this helped!
T = c + cb
t - c = cb
(t - c)/c = b
b = (t - c)/c
70/81 is 7/81+7/9 as a proper fraction
Answer:
You can use Gaussian Elimination.
Double both sides of the first equation and add the second equation.
6x + 4y = 8
5x - 4y = 3
---------------
11x = 11
x = 1
5 - 4y = 3
-4y = -2
y = 1/2
Step-by-step explanation:
