The answer is: 83 + 12√35
(a + b)² = a² + 2ab + b²
In (2√5 + 3√7)², a = 2√5, b = 3√7
Just substitute a and b:
(a + b)² = a² + 2ab + b² = (2√5)² + 2 * 2√5 * 3√7 + (3√7)² =
= 2²√5² + 2 * 2 * 3 * √5 * √7 + 3²√7² =
= 4 * 5 + 12 * √(5*7) + 9 * 7 =
= 20 + 12 *√35 + 63 =
= 83 + 12√35
Answer:
x=5 twice
Step-by-step explanation:
x^2-10x+25=0
multiply the coefficient of x^2 and the last term
1X25=25
find two numbers you can multiply to get 25 and add to get -10
-5 + (-5)=-10 the middle term
replace -10x with -5x -5x and solve the equation
x^2-5x-5x+25=0
factorise by grouping
x(x-5)-5(x-5)=0
(x-5)(x-5)=0
Either x-5=0,x=5 or x-5=0,x=5
Therefore x=5 twice.
Total of $7.75
13 more quarters than nickels
15 nickels = $0.75
28 quarters = $7.00
28 - 15 = 13 coins
$7.00 + $0.75 = $7.75
She has 15 nickels and 28 quarters.
Answer:
Step-by-step explanation:
36 d²-36 d+9=9(4d²+4d+1)
=9[4d²+2d+2d+1]
=9[2d(2d+1)+1(2d+1)]
=9(2d+1)(2d+1)
=9(2d+1)²
=[3(2d+1)]²
=(6d+6)²
length=6d+6
perimeter=4(6d+6)=24d+24
when d=2
length=6×2+6=18in
perimeter=4×18=72 in
area=18²=324 in²
Answer:
45/100 = 0.45
Step-by-step explanation:
Divide 9 by 20.
9/20 = 0.45
Now write 36/100 as a decimal.
36/100 = 0.36
Write 45/100 as a decimal: 0.45
Answer: 45/100 = 0.45