Answer:
Step-by-step explanation:
Simplifying
2x + 13 = 0
Reorder the terms:
13 + 2x = 0
Solving
13 + 2x = 0
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-13' to each side of the equation.
13 + -13 + 2x = 0 + -13
Combine like terms: 13 + -13 = 0
0 + 2x = 0 + -13
2x = 0 + -13
Combine like terms: 0 + -13 = -13
2x = -13
Divide each side by '2'.
x = -6.5
Simplifying
x = -6.5
Answer:
Sister = 15 years old
Brother = 12 years old
Step-by-step explanation:
Right now, if the brother is B years old and the sister is S years old, B = (4/5)S because the ratio from brother to sister is 4:5, so if one unit is X, B = 4X and S = 5X
Three years ago, the brother was B-3 years old and the sister was S-3 years old. Keeping one unit as X, we have
B = 3X
S = 4X
B-3 = (3/4)(S-3)
Therefore, we have a system of equations
B = (4/5)S
B-3 = (3/4)(S-3)
Substitute (4/5)S for B into the second equation to only have one variable
(4/5)S - 3 = (3/4)(S-3)
(4/5)S - 3 = (3/4)S - 9/4
add 3 to both sides and subtract (3/4)S from both sides to isolate the variable and its coefficient
(1/20)S = 3/4
multiply both sides by 20 to isolate the S
S = 15
B = (4/5)S = 12
Answer:
Step-by-step explanation:
In the morning he works four hours and 15 minutes and in the afternoon he works four hours and 15 minutes for a total of eight hours and 30 minutes. 30 minutes is 1/2 of an hour so he works for a total of 8 1/2 hours. Multiply this by his hourly rate which is $15 and this gives you $127.50
15 x 8.5 = 127.5
Answer:
First number =26
Second number =49
Step-by-step explanation:
Question:
The sum of two numbers is 75. The second number is 3 less than twice the first. Find the numbers.
Given:
Sum of two numbers = 75
The second number is 3 less than twice the first.
To find the numbers.
Solution:
Let the first number be = 
Let second number be = 
The sum equation can be given as:
It is given that the second number is 3 less than twice the first.
This can be given as:
Substituting the value of in terms of in the sum equation.
Combining like terms.
Adding 3 both sides.
Dividing both ides by 3.
Substitution in the second equation to find .
Thus, first number =26 and second number =49.
