Let m the tens digit and n the ones
the Original number is 10m+n
7(m+n) =10m+n
7m+7n=10m+n
6n=3m
Reversing the number 10n+m
10n+m=18+n+m
9n=18
n=2
6n=3m
6(2)=3m
3m=12
m=4
the number is 10m+n=10(4)+2=42
Answer: N=-4
Step-by-step explanation:
STEP
1
:
STEP
2
:
Pulling out like terms
2.1 Pull out like factors :
-4n - 9 = -1 • (4n + 9)
Equation at the end of step
2
:
-3 • (4n + 9) - 21 = 0
STEP
3
:
STEP
4
:
Pulling out like terms
4.1 Pull out like factors :
-12n - 48 = -12 • (n + 4)
Equation at the end of step
4
:
-12 • (n + 4) = 0
STEP
5
:
Equations which are never true:
5.1 Solve : -12 = 0
This equation has no solution.
A a non-zero constant never equals zero.
Solving a Single Variable Equation:
5.2 Solve : n+4 = 0
Subtract 4 from both sides of the equation :
n = -4
One solution was found :
n = -4
Answer: 28/r+4
Step-by-step explanation: Divide each term by r + 4 and simplify
Answer:
Step-by-step explanation:
Brain correctly use a method of completing the square to solve the equation:
His First Step is to: Take the Constant Term to the Right Hand Side
The Next Step Would be to:
- Divide the Coefficient of x by 2
- Square It
- Add it to both Sides
In this case, the Coefficient of x = 7
- Divided by 2 =
- Squaring It, we have:
It is this number that is added to both sides in the manner below:
The answer to this problem is A 10
