Answer:
A
Step-by-step explanation:
Answer:
Step-by-step explanation:
(a+ b)² = a² + b² + 2ab
(2x + y)² = (2x)² + y² + 2*2x *y
= 4x² + y² + 4xy
(a- b)² = a² + b² - 2ab
(3x - 2y)² = (3x)² + (2y)² - 2*3x *2y
= 9x² + 4y² - 12xy
(a - b)(a +b) = a² - b²
(x - 4y(x + 4y) = x² - (4y)²
= x² - 16y²
(2x + y)² - (3x - 2y)² + (x - 4y)(x +4y)
= 4x² + y² + 4xy - (9x² + 4y² - 12xy) + x² - 16y²
= 4x² + y² + 4xy - 9x² - 4y² + 12xy + x² - 16y²
= 4x² - 9x² + x² + y² - 4y² - 16y²+ 4xy + 12xy
= -4x² - 19y² + 16xy
Answer:
Dimes = x = 52
Nickels = y = 39
Step-by-step explanation:
Let
Dimes = x
Nickels = y
x + y = 91 (1)
0.10x + 0.05y = 7.15 (2)
From (1)
x = 91 - y
Substitute x = 91 - y into (2)
0.10x + 0.05y = 7.15
0.10(91 - y) + 0.05y = 7.15
9.10 - 0.10y + 0.05y = 7.15
- 0.10y + 0.05y = 7.15 - 9.10
-0.05y = -1.95
y = -1.95 / 0.05
= 39
Substitute y = 39 into (1)
x + y = 91
x + 39 = 91
x = 91 - 39
x = 52
Dimes = x = 52
Nickels = y = 39
Answer:
1)72=-8-5n
+8 +8
2)80=-5n
/-5 /-5
3)-16=n
Step-by-step explanation:
The perimeter is the distance all the way around.
That's the sum of all the sides.
A triangle has 3 sides.
In an equilateral triangle, they're all the same length.
If one of them is 9.9 cm, then all of them add up to (3) · (9.9 cm) .
