Answer: 11 or -16
Step-by-step explanation:
The square of a number increased by 5 times the number is equal to 176.
Let the number be x
Then, x²+5x=176
x²+5x-176=0
We use splitting the middle term method
x²+16x-11x-176=0
x(x+16)-11(x+16)=0
(x-11)(x+16)=0
i.e. either x-11=0 or x+16=0
i.e. either x=11 or x=-16
Hence, the number is either 11 or -16
