Answer:
Step-by-step explanation:
To be rational means to be able to express the result as the ratio of two whole numbers.
a) 4/7 + (-1/3) = 12/21 - 7/21 = 5/21 so rational
b) √(4) • 2/5 = ±2 • 2/5 = ±4/5 so both solutions are rational
Answer:
Step-by-step explanation:
First you want to understand that every time a radio wave goes 300,000,000 meters a second passes, literally what meter per second means. of course it doesn't go that far, it goes 384,000 one way and then the same distance back, which makes 768,000. Under a third of the distance to make 1 second, so it will be less than one second.
You also want to understand the formula for speed. speed = distance / time. Whch also means, to find time you can change it to be time = distance / speed. And hey, we have distance and speed. 768,000 / 300,000,000 = .00256, I'll leave the significant figures to you unless you need help with them. but that's .00256 of a second. or .00256 s
The answer is 16 ft because 6 ft tall over 4 feet 6 inches (4.5) is equal to x (tree's height) over 12 ft. You cross multiple and get 72 = 4.5x then you take 72 and divide by 4.5 to get the tree's height

Answer:
(0.5, 4 )
Step-by-step explanation:
Given the 2 equations
2x + 3y = 13 → (1)
4x - y = - 2 → (2)
Multiplying (2) by 3 and adding to (1) will eliminate the term in y
12x - 3y = - 6 → (3)
Add (1) and (3) term by term to eliminate y
14x = 7 ( divide both sides by 14 )
x = 0.5
Substitute x = 0.5 into either of the 2 equations and evaluate for y
Substituting into (1)
2(0.5) + 3y = 13
1 + 3y = 13 ( subtract 1 from both sides )
3y = 12 ( divide both sides by 3 )
y = 4
Solution is (0.5, 4 )