Question Factor the expression 3(7z−5) Evaluate 21z−15Solution 3(7z−5) Show Solution Find the roots z=75Alternative Form z=0.7˙14285˙ Evaluate 21z−15To find the roots of the expression,set the expression equal to 0 21z−15=0Move the constant to the right-hand side and change its sign 21z=0+15Removing 0 doesn't change the value,so remove it from the expression 21z=15Divide both sides 2121z=2115Divide the numbers z=2115Solution z=75Alternative Form z=0.7˙14285˙ Show Solution