Answer:
(x+1)(x+7)
Explanation
To find the factor of x^2+8x+7 you have to find the missing numbers m and n. Ex. (x+m)(x+n) If you evaluate this expression you will get
x^2+(m+n)x+mn. So from here you just need to find the numbers that fulfill the conditions of m and n. You can do this by just guessing and checking.