How do you solve #(3x-1)/(5x+4 )= 4#?

2 Answers
Mar 28, 2018

#x=-1#

Explanation:

#"to eliminate the fraction multiply both sides by "5x+4#

#cancel(5x+4)xx(3x-1)/cancel(5x+4)=4(5x+4)#

#rArr3x-1=4(5x+4)larrcolor(blue)"distribute"#

#rArr3x-1=20x+16#

#"subtract "20x" from both sides"#

#3x-20x-1=cancel(20x)cancel(-20x)+16#

#rArr-17x-1=16#

#"add 1 to both sides"#

#-17xcancel(-1)cancel(+1)=16+1#

#rArr-17x=17#

#"divide both sides by "-17#

#(cancel(-17) x)/cancel(-17)=(-17)/17#

#rArrx=-1#

#color(blue)"As a check"#

Substitute this value into the left side of the equation and if equal to the right side then it is the solution.

#(-3-1)/(-5+4)=(-4)/(-1)=4=" right side"#

#rArrx=-1" is the solution"#

Mar 28, 2018

#(5x+4)*(3x-1)/(5x+4)=4*(5x+4)#
therefore #3x-1= 20x+16#
#-16-1=20x-3x#
#-17/17=17x/17# therefore #x=-1#

Explanation:

you firstly dissolve the denominator on the left side by multiplying with #5x+4# both sides. Then collect like terms, the once with the variable #x# on one side and one with real numbers on the other side. then solve to get the answer.