# How do you use cross products to solve #6.8/z=2/5#?

##### 1 Answer

Aug 2, 2017

#### Explanation:

#"given an equation with 2 equal fractions then"#

#•color(white)(x)a/b=c/drArraxxd=bxxc#

#rArrcolor(blue)(6.8)/color(red)(z)=color(red)(2)/color(blue)(5)larr"cross-multiply"#

#rArrcolor(red)(z)xxcolor(red)(2)=color(blue)(6.8)xxcolor(blue)(5)#

#rArr2z=34#

#"divide both sides by 2"#

#(cancel(2) z)/cancel(2)=34/2#

#rArrz=17#

#color(blue)"As a check"#

#"left side "=6.8/17=0.4=2/5=" right side"#

#rArrz=17" is the solution"#