3x = y and x - 2y = 10

Rewrite equations:

3x=y;x−2y=10

Step: Solve3x=yfor y:

3x=y

3x+−y=y+−y(Add -y to both sides)

3x−y=0

3x−y+−3x=0+−3x(Add -3x to both sides)

−y=−3x

−y

−1

=

−3x

−1

(Divide both sides by -1)

y=3x

Step: Substitute3xforyinx−2y=10:

x−2y=10

x−23x=10

−5x=10(Simplify both sides of the equation)

−5x

−5

=

10

−5

(Divide both sides by -5)

x=−2

Step: Substitute−2forxiny=3x:

y=3x

y=(3)(−2)

y=−6(Simplify both sides of the equation)

Step-by-step explanation:

1. sometimes

2. never true

3. sometimes

step-by-step explanation:

these are pretty self explanatory if you know what supp right and com angles are

use distributive property on all like terms and change your signs if you have a double negative or if you have positive/negative