Answer:
I think Jenny will be able to do 9 pillows with the lace trim.
I think its C sorry if its wrong!
Use cosine rule,
cos(A)=(b^2+c^2-a^2)/(2bc)
=(10^2+12^2-6^2)/(2*10*12)
=13/15
A=29.926 degrees.................................(A)
cos(B)=(c^2+a^2-b^2)/(2ca)
=(12^2+6^2-10^2)/(2*12*6)
=5/9
B=56.251 degrees.................................(B)
cos(C)=(a^2+b^2-c^2)/(2ab)
=(6^2+10^2-12^2)/(2*6*10)
=-1/15
C=93.823 degrees.................................(C)
Check:29.926+56.251+93.823=180.0 degrees....ok
Chapter : Algebra
Study : Math in Junior high school
x = 7 + √40
find √x of √x + 1
= √x + 1
= √(7+√40) + 1
in Formula is :
= √7+√40 = √x + √y
= (√7+√40)² = (√x + √y)²
= 7+√40 = x + 2√xy + y
= 7 + √40 = x + y + 2√xy
→ 7 = x + y → y = 7 - x ... Equation 1
→ √40 = 2√xy → √40 = 2.2√10 = 4√10
= xy = 10 ... Equation 2
substitution Equation 1 to 2 :
= xy = 10
= x(7-x) = 10
= 7x - x² = 10
= x² - 7x + 10 = 0
= (x - 5)(x - 2) = 0
= x = 5 or x = 2
Subsitution x = 5 and x = 2, to equation 1
#For x = 5
= y = 7 - x
= y = 7 - (5)
= y = 2
#For x = 2
= y = 7 - x
= y = 7 - (2)
= y = 5
and his x and y was find :
#Equation 1 :
= x = 5 and y = 2
#Equation 2 :
= x = 2 and y = 5
So that :
√7+√40 = √x + √y
= √7+√40 = √2 + √5
And that is answer of question :
= √2 + √5 + 1
To solve this I'm going to split the middle term.
First multiply the first and last terms:
24x^2
So find two numbers that multiply to 24x^2 and add to 11x.
This would be 3x and 8x
Rewrite the problem as
4x^2+3x+8x+6
Take the first and 3rd and 2nd and 4th terms
4x^2 and 8x
and
3x and 6
Factor by grouping
Take out a 4x for the first group to get 4x(x+2)
Take out a 3 for the 2nd group to get 3(x+2)
Rewrite as (4x+3)(x+2)
Hope this helps.
