How do you solve and check #5(x-2) + (-9) = -7(1-x)#?
1 Answer
Mar 4, 2017
Explanation:
distribute the brackets on both sides of the equation.
#rArr5x-10-9=-7+7x# simplifying gives.
#5x-19=-7+7x# collect terms in x, on the left side and numeric values on the right side.
subtract 7x from both sides.
#5x-7x-19=-7cancel(+7x)cancel(-7x)#
#rArr-2x-19=-7# add 19 to both sides.
#-2xcancel(-19)cancel(+19)=-7+19#
#rArr-2x=12# divide both sides by - 2
#(cancel(-2) x)/cancel(-2)=12/(-2)#
#rArrx=-6# To check that x = - 6 is the solution, substitute this value into the equation and if the left side equals the right side then it is the solution.
#color(blue)"As a check"#
#"left side "=5(-6-2)-9=(5xx-8)-9=-40-9=-49#
#"right side "=-7(1-(-6))=(-7xx7)=-49#
#rArrx=-6" is the solution"#