2.4k views
2 votes
If x + y equals to 10 and x - 2 y equals 8 what is the value of 3 y

User Mororo
by
7.0k points

1 Answer

3 votes

We have this first condition given:


x+y=\text{ 10 (1)}

And the second one:


x-2y=\text{ 8 (2)}

If we solve for x from equation (1) we got:


x=\text{ 10}-y\text{ (3)}

And if we solve for x from equation (2) we got:


x=\text{ 8+2y (4)}

Now we can set equal equations (3) and (4)


10-y=\text{ 8+2y}

And solving for y we got:


18=\text{ 3y }\rightarrow\text{ y= }(18)/(3)=\text{ 6}

Final answer:


y=\text{ 3}\cdot6\text{ = 18}

User JackW
by
7.0k points