All sides are the same, hence, all three angles are the same, and each one of them is 60 degrees. Due to that:
7x + 4 = 60
7x = 56
x = 56/7 = 8
8y + 12 = 60
8y = 48
y = 48/8 = 6
Answer:
D
Step-by-step explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r is the radius
here (h, k) = (- 6, - 8), thus
(x + 6)² + (y + 8)² = r²
The radius is the distance from the centre to a point on the circle
Calculate r using the distance formula
r = √ (x₂ - x₁ )² + (y₂ - y₁ )²
with (x₁, y₁ ) = (- 6, - 8) and (x₂, y₂ ) = (0, 0)
r = 
= 
= 
= 10
Hence
(x + 6)² + (y + 8)² = 100 → D
1 litre of 10% solution contains 100mL of iodine
1 litre of 90% solution contains 900mL of iodine
Mixing them will produce 2 litres of solution containing 1000mL of iodine which is 50% iodine.
To produce 8 litres of 50% iodine they can mix 4 litres of 10% and 4 litres of 90%
Answer:
x=1, y=1. (1, 1). The answer is D).
Step-by-step explanation:
3x-5y=-2
4x-7y=-3
--------------
4(3x-5y)=4(-2)
-3(4x-7y)=-3(-3)
------------------------
12x-20y=-8
-12x+21y=9
--------------------
y=1
3x-5(1)=-2
3x-5=-2
3x=-2+5
3x=3
x=3/3
x=1
Answer:
x>1
Step-by-step explanation:
x + 18 > 19
Subtract 18 from each side
x + 18-18 > 19-18
x>1
