Question

4 times a number and 5 times the same number added to 75 gives 156. Find the number.
please give full solution​

Answer 1

Answer:

9

Step-by-step explanation:

Let the unknown no. be x

Then according to the statement,

4x + 5x + 75 = 156

9x + 75=156

9x= 156 - 75

9x= 81

x = 81/9

x = 9

Answer 2

Answer:

a²-b²+2bc-c² =a² - (b² -2bc +c²)

=a² - (b-c)²

=(a-(b-c))(a+(b-c))

‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ [ using identity a²-b² =(a-b)(a+b) ]

= (a-b+c)(a+b-c)

hence.,a²-b²+2bc - c² = (a-b+c)(a+b-c)