Question 577382
{{{0.7(15)-x=0.6(15-x)}}}
{{{7(15)/10-x=6(15-x)/10}}}
{{{105/10-x=(90-6x)/10}}}
{{{(105-10x)/10=(90-6x)/10}}}
{{{(105-10x)/cross(10)=(90-6x)/cross(10)}}}
{{{105-10x=90-6x}}}
{{{-10x+6x=90-105}}}
{{{-4x=-15}}}
{{{-4x/-4=-15/-4}}}
{{{cross(-4)x/cross(-4)=-15/-4}}}
{{{x=15/4}}}
{{{x=(3&3/4)}}}


Check
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{{{0.7(15)-x=0.6(15-x)}}}
Put {{{x=15/4}}}
{{{0.7(15)-15/4=0.6(15-15/4)}}}
{{{7(15)/10-15/4=6(15-15/4)/10}}}
{{{105/10-15/4=6((60-15)/4)/10}}}
{{{(210-75)/20=6((45)/4)/10}}}
{{{135/20=6(45/4)(1/10)}}}
{{{cross(135)/cross(20)=6(45/40)}}}
{{{27/4=cross(6)(45)/cross(40))}}}
{{{27/4=3(45)/20))}}}
{{{27/4=3(cross(45))/cross(20)}}}
{{{27/4=3(9)/4}}}
{{{27/4=27/4}}}


OR
{{{0.7(15)-x=0.6(15-x)}}}
{{{10.5-x=9-0.6x)}}}
{{{-x+0.6x=9-10.5)}}}
{{{-0.4x=-1.5)}}}
Cancel out (-) from both sides
{{{0.4x=1.5)}}}
{{{0.4x/0.4=1.5/0.4)}}}
{{{cross(0.4)x/cross(0.4)=1.5/0.4)}}}
{{{x=1.5/0.4)}}}
Multiply and Divide Right hand side by 10
{{{x=(1.5/0.4)(10/10))}}}
again
{{{x=15/4)}}}
or
{{{x=3.75)}}}


Check
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{{{0.7(15)-x=0.6(15-x)}}}
Put {{{x=3.75)}}}
{{{0.7(15)-3.75=0.6(15-3.75)}}}
{{{10.5-3.75=9-2.25)}}}
{{{6.75=6.75)}}}