Answer:

Step-by-step explanation:
move variable to the right-hand side and change its sign

divide both sides of the equation

Answer:
geraldo has 9 marbles and yan has 12
Step-by-step explanation:
x + (x-3) = 21
x + x - 3 = 21
2 x - 3 = 21
Explanation:
In this problem, let us first analyze the situation. It says here that Geraldo and Yan both had marbles of their own. The problem states that together, they have a total of 21 marbles. However, we know here from the problem that they have different number of marbles each. Geraldo seems to have lesser number of marbles than Yan. Yan have three marbles more than Geraldo.
We can write the equation starting from assigning the unknown.
We'll use x.
x is the number of marbles that Yan have.
if x is Yan's, then, we can say that x-3 is Geraldo's.
Put them together into the equation.
Yan's plus Geraldo's is equal to 21.
Substitute using the represented unknowns.
x + (x-3) = 21.
In solving, we can also rule out that:
x + x - 3 = 21
2 x - 3 = 21
2 x = 21 + 3
2 x = 24
x = 12
x - 3 = 9
Yan has 12 marbles
and Geraldo has 9 marbles.
The correct answer is C "never."
The hypotenuse in a 30-60-90 triangle is the shorter leg doubled. So, it's 2x where x is the shorter leg.
In fact, the square root of two is not used to calculate any other sides in a 30-60-90 triangle. The shorter leg is x, the medium leg is x√3, and the hypotenuse is 2x.
Answer:
B
Step-by-step explanation:
For each box, there is 1 defective lightbulb. Therefore, a delivery of 4 boxes will have 4 defective lightbulbs. A delivery of 2 boxes has 2 defective lightbulbs. 4 defective lightbulbs subtracted by 2 defective lightbulbs equals 2 more defective lightbulbs in 4 boxes than 2. Therefore, it is B.