Answer:
Gina is 12 years old
Step-by-step explanation:
First, we will have to write these statements mathematically and then solve.
Let Gina's age be x, let Gina's brother's age be y and let Gina's sister's age be z.
The second statement"Gina's older sister is twice Gina's age" can be mathematically written as: z =2 x ---------------------------(1)
The next statement "Gina's brother is half Gina's age" can be mathematically written as y = 
---------------------------------------(2)
Then the next statement "the sum of their ages is 42" can be mathematically written as: x + y + z = 42 ----------------------------(3)
We can now proceed to solve;
Substitute equation (1) and equation(2) into equation (3)
x + y + z = 42
x + + 2x = 42
Multiply through by 2
2x + x + 4x = 84
7x = 84
Divide both-side of the equation by 7
= 
x = 12
Therefore, Gina is 12 years old
Answer:
-17
Step-by-step explanation:
- 5 * (6 + 4) ÷ 2
Following PEMDAS, we must focus on the parenthesis first.
- 5 * (6 + 4) ÷ 2
- 5 * (10) ÷ 2
Now we will focus on the exponent:
- 5 * 10 ÷ 2
8 - 5 * 10 ÷ 2
Now Multiplication/Division.
This is where you must follow the order in the equation where you see the multiplication sign first, so you multiply first.
8 - 5 * 10 ÷ 2
8 - 50 ÷ 2
Next, Divide:
8 - 50 ÷ 2
8 - 25
Subtract:
8 - 25
-17
- 5 * (6 + 4) ÷ 2 = -17.
The square root of 2.25 is 1.5
Diagram not attached, please add the question.
Answer:
k = -1/240
Step-by-step explanation:
to evaluate the value of k in the expression 1/3k+80=1/2k+120
we have
1/3k+80=1/2k+120
collect the like terms for easy evaluation
1/3k - 1/2k = 120 -80
1/3k - 1/2k = 40
find the lcm
2 - 3/6k = 40
-1/ 6k = 40
cross multiply
6k x 40 = -1
240k = -1
divide both sides by 240
240k/240 = -1/ 240
k = -1/240
therefore the value of k in the expression 1/3k+80=1/2k+120 is equals to -1/240
