Posted by Ashley on .
Solving Systems by Substitution:
2. x=14y
2x+7y=3
I need help learning how to do this problem stepbystep

algebra 
Reiny,
your first equation says that
x = 14y
so "substitute" 14y wherever you see x in the other equation
2x+7y=3
2(14y) + 7y = 3
2  8y + 7y = 3
y = 1
y = 1
next sub that y = 1 back into the first equation
x = 1  4(1) = 1+4 = 5 
algebra 
Chopsticks,
x = 14y
2x+7y=3
Starting with the first equation
since x = 1  4y
Plug that in to the second equation
2(14y)+7y=3
2 8y + 7y = 3
2  y = 3
2/2  y = 3/2
 y = 3/2
Since why can't be negative, move the negative over to the other side
y = 3/2
Okay we found what Y is now plug that into the first equation
x = 14(3/2)
x = 1 + 6
x = 7
so the answer is (7,3/2)
I'm pretty sure this is right, but I hope a real tutor comes and say for sure 
algebra 
Chopsticks,
Oh sorry, I did my math wrong and Divided instead of subtracting.