Respuesta :
Answer:
10+51+17=78
Step-by-step explanation:
Alright, so at first I just took a random number and kept on working it out until I got the exact answer as 78. Finally, i got the third number as 17. Now, i know the third number is 7 more than the first so I have to subtract 17 and 7, 17-7=10. So the first number is 10. Ok, now i know that the second number is 3 times the third number (17) so you should multiply, 17x3=51. 51 is the 2nd number.
1st number=10
2nd number=51
3rd number=17
Add them, 10+51+17=78.
Answer:
- First number = 10
- Second number = 51
- Third number = 17
Step-by-step explanation:
In the question we are given ,
- Sum of three numbers is 78
- Third no. is 7 more than first
- Second no. is 3 times third
So , we are assuming that ,
- Let first no. be x
- Third no. be x + 7 ( because in question it is given that third number is 7 more than the first number ) .
- Second no. be 3 ( x + 7 ) ( because in the question it is given that second no. is three times the third )
We are finding the solution by adding all these term and equating it with 78 because sum of these three numbers is equal to 78 .
Here we go ,
[tex] \longrightarrow \: x + 3(x + 7) + x + 7 = 78[/tex]
Step 1 : Solving the bracket part :
[tex] \longrightarrow \: \blue{x }+ \blue{ 3x} + \red{21} + \blue{ x} + \red{7 }= 78[/tex]
Step 2 : Adding like terms :
[tex] \longrightarrow \:5x + 28 = 78[/tex]
Step 3 : Transposing 28 to right hand side :
[tex] \longrightarrow \:5x = \green{78} - \green{28}[/tex]
Step 4 : Subtracting 28 from 78 :
[tex] \longrightarrow \:5x = 50[/tex]
Step 5 : Transposing 5 to right hand side :
[tex] \longrightarrow \:x = \cancel \frac{50}{5} [/tex]
Step 6 ; Cancelling 50 with 5 :
[tex] \longrightarrow \: \purple{\boxed{x = 10}}[/tex]
Therefore value of ,
- x [ first number ] = 10
- 3(x + 7 ) [ second number ] = 51
- x + 7 [ third number ] = 17
Verification :
We are verifying our answer by adding the three numbers and it must be equal to 78 .
- 10 + 51 + 17 = 78
- 61 + 17 = 78
- 78 = 78
- L.H.S = R.H.S
- Hence , Verified.
Therefore , our answer is correct .