If #A=(a+b)/2 * h# how do you write this as an equation for #a#?

2 Answers
Sep 13, 2017

#color(red)(a=(2A)/h-b)#

Explanation:

If
#color(white)("XXX")A=(a+b)/2 * h#

then
#color(white)("XXX")A/h =(a+b)/2#

#color(white)("XXX")(2A)/h=a+b#

#color(white)("XXX")(2A)/h-b=a#

Sep 13, 2017

#a=(2A)/h-b#

Explanation:

#"multiply both sides by 2"#

#2A=cancel(2)xx((a+b)h)/cancel(2)#

#"rArrh(a+b)=2A#

#"divide both sides by h"#

#cancel(h)/(cancel(h))(a+b)=(2A)/h#

#"subtract b from both sides"#

#acancel(+b)cancel(-b)=(2A)/h-b#

#rArra=(2A)/h-b#