Q. If ∣2x−7∣≤8, what is the greatest possible value of ∣x−7∣?(A) −21(B) 0(C) 21(D) 215
Absolute Value Definition: To solve the inequality ∣2x−7∣≤8, we need to consider the definition of absolute value, which states that ∣a∣≤b implies −b≤a≤b for any real number a and non-negative real number b.So, we can write the inequality as two separate inequalities:−8≤2x−7≤8
Solving Left Inequality: Now, we solve the left inequality for x:−8≤2x−7Add 7 to both sides:−1≤2xDivide both sides by 2:−21≤x
Solving Right Inequality: Next, we solve the right inequality for x:2x−7≤8Add 7 to both sides:2x≤15Divide both sides by 2:x≤215
Combining Inequalities: Combining both inequalities, we get the solution for x:−21≤x≤215
Finding Greatest Value: Now, we need to find the greatest possible value of ∣x−7∣. To do this, we need to consider the distance of x from 7 on the number line. The greatest distance will occur at the endpoints of the interval for x.We calculate ∣x−7∣ at both endpoints:For x=−21: ∣x−7∣=∣∣−21−7∣∣=∣∣−(21+214)∣∣=∣∣−215∣∣=215For x=215: ∣x−7∣=∣∣215−7∣∣=∣∣215−214∣∣=∣∣21∣∣=21
Finding Greatest Value: Now, we need to find the greatest possible value of ∣x−7∣. To do this, we need to consider the distance of x from 7 on the number line. The greatest distance will occur at the endpoints of the interval for x. We calculate ∣x−7∣ at both endpoints: For x=−21: ∣x−7∣=∣∣−21−7∣∣=∣∣−(21+214)∣∣=∣∣−215∣∣=215 For x=215: ∣x−7∣=∣∣215−7∣∣=∣∣215−214∣∣=∣∣21∣∣=21 Comparing the two values, we see that 215 is greater than x0, so the greatest possible value of ∣x−7∣ is 215.