Problema Solution
a number is multiplied by half of it.15 is added to the product.the sum is .find the number
Answer provided by our tutors
suppose the number to be x
multiply it with x/2 and then add 15
we'll have
x*x/2 +15 =sum(you did not give e.g. it is 23)
x2/2 +15=23
x2/2=8
x2=16
x2 -16 = 0
factoring x2 -16 we'll have (x-4)(x+4)
(x-4)(x+4)=0
now x can be both 4 and -4