Okay so let's first try to get the first equation in the same form as the second with y on one side.
We have 7x-y=10 so we will subtract 7x from both sides and we now have :
-y=-7x+10
Now we can add both equations!
-y=-7x+10
+ y=-7x+2
We end up with 0=-14x+12
subtract 12 from both sides and we have -12=-14x
divide by -14 and we have 12/14=x we can simply that fraction to 6/7.
Now that we know x=6/7, we can plug it into the equations to find y!
7(6/7)-y=10
7(6/7)=6 so we now have 6-y=10
Subtract 6 and we now have -y=4. We want to also divide the negative sign since there's also an invisible one attached to it so the answer is y=-4
Let's plug in 6/7 into the second one to see if we get -4 too!
y=-7(6/7)+2
y=-6+2
y=-4
So there we have it! x=6/7 and y= -4! Sorry i took so long!
Carletta works at the rate
x = (1 board)/(12 hours) = 1/12 mb/hr
Johnathan works at the rate
y = (1 board)/(16 hours) = 1/16 mb/hr
The combined working rate is
1/12 + 1/16 = 7/48 = 0.1458 mb/hr
The time to build a mother board (mb) when working together is
(1 mb)/(0.1458 mb/hr) = 6.8587 hrs = 7 hours (nearest hour)
Answer: 7 hours
Yea it's good but make sure to check your answers to see if you did anything wrong.