a The recommended weight of a soccer ball is 430 grams. The difference between the recommended weight and the actual weight x can be expressed as x- 430. Since we are not interested in the sign, we will only consider an of the expression.
|x- 430|In the exercise we are told that the weight can vary up to 20 grams. Since we are looking for the minimum and maximum weights of the ball, we need to find for what x the expression above is equal to 20.
|x- 430|= 20
To solve for x, we will split our into two separate cases.
|x-430|=20
lc x-430 ≥ 0:x-430 = 20 & (I) x-430 < 0:x-430 = - 20 & (II)
lcx-430=20 & (I) x-430=- 20 & (II)
(I), (II): LHS+430=RHS+430
lx=450 x=410
The weight cannot be less than 410 grams, and it cannot be more than 450 grams.